She is daughter of former Tory MP Shaun Woodward. Her mother is Sainsbury's heiress Camilla Sainsbury.
You probably know her as Deliciously Ella, the woman behind the eponymous healthy eating blog she started in 2012 during her time as a student at St. Andrew's University in Scotland.
Over the past three years, the blog has generated more than 100 million hits.
"With eating well there's a perception that it's depressing," Ella told Business Insider. "People think they're just going to meditate and eat kale. Our main aim as a company is to take natural food and celebrate it and make it delicious, vibrant and beautiful — something you want to be a part of rather than that push towards fad diets."
Mills was diagnosed with Postural Tachycardia Syndrome (POTS) in 2011, which effects the nervous system.
"I’d been in hospital and in bed for a long time taking loads of medication," she said. "I was interested in different things I could do to manage the condition."
She found that changing her diet and lifestyle slowly began to help, and was inspired to start the blog. This included cutting out gluten and going vegan.
On the day we meet, she's visiting the newly-opened second Mae Deli location on Mayfair's Weighhouse Street. She owns it with her 32-year-old husband and business partner Matthew Mills. They opened their first deli on Seymour Place in Marylebone in December last year.
"Matt started working with me a year ago and it has changed peoples' perceptions," Ella said. She added that this has helped broaden the appeal of her brand.
The newest Mae Deli, which takes the first letters of their names along with the name of their dog, Austin, opened on 1 November. "We’re 11 months in with three sites open now," Matt said.
Ella was introduced to Matt by her father in 2015. Matt said: "My mum [Labour peer and former cabinet minister Tessa Jowell] and Ella's dad worked together. We met and three months later we were engaged."
The two decided to go into business together four months after meeting.
"We want for a walk last summer not knowing we were going to do this and by the time we got back, we decided to start working together," Matt said.
"We went on our first date towards the end of March 2015, got engaged on August 1, and got married in April of this year," Ella said. "We're not really ones to play it safe."
While the delis have hit the ground running, it was the recipe app Ella launched in February 2014 that got the business off the ground.
"The app funded everything to start with," Ella said. "It went to number one overnight and has stayed in the top five food and drink apps in the UK app store ever since. It was this constant ticker that allowed everything to get started."
Her first cookbook followed in January 2015 and was the fastest-selling debut cookbook ever in the UK. She released her second a year later.
At 9am the new Mayfair deli in Mayfair is already packed. It has only been open for three weeks and took two months to build.
"Lunch is the biggest part of what we do – there’s a queue out the door every day, and it’s filled with people you wouldn’t expect to be here," Ella said. "We don’t want it to be a niche thing."
The most popular hot dishes are the cauliflower and lentil dahl and a five bean chilli.
But it's the brownies that are the bestseller. "We keep selling out," Ella said.
"One of the great secrets and tricks to Ella’s success is the fact that when you’re eating with Ella you don’t feel like you’re eating something that’s super healthy," said Matt.
He said that while he's always watched his diet due to sport – he was previously a professional golfer – he's learned a lot about "this side of eating" since being with Ella.
Another Mae Deli is set to open in Herne Hill early next year, but Ella and Matt don't plan to roll the delis out any further. "We want the quality to be high and look and feel different, and that’s very challenging on scale," Ella said.
They do, however, hope to open a proper restaurant in London over the next year or two.
"We can’t afford to do it right now because it’s prohibitively expensive, but we would like to do one at some stage," Matt said. He added that with Brexit looming there is "a lot of uncertainty."
"We’re not putting growth on hold – we’re still investing, but we're trying to do things where we can be a bit more nimble."
Ella started the day meeting her publisher at the new deli to see the first printed version of her new cookbook, "Deliciously Ella with Friends," which comes out on 26 January.
It features over 100 recipes, from which Ella and her team are trying to select 10 to 15 to use in a press pack.
"I tried to get the team in the book to get a sense of fun and sharing," she said. "I also got all of my family in it."
She said that while she prepares the recipes beforehand, a cook and food stylist prepares them for the book shoot. "We do 10 photos a day, which is quite a lot."
"It's full of natural but accessible recipes," she said. "It’s hearty – it’s not just pages of steamed greens."
Her favourite recipes in the book include sweet potato falafels, a three-bean stew and a chickpea chilli.
"We go through a few rounds of recipe testing," she said. "I’ll try it a few times then send it to our office to try it. It normally takes about five tries."
She and Matt see the business as three separate things: Deliciously Ella, which is the books, the app, the blog, events and talks; the delis; and the products.
"Matt and I bring different skills to the table," Ella said. "I work on the brand side of it – everything you look, see, eat, feel and connect to and engage with, that’s what I do and where my skills lie in the creativity of it."
She added: "Matt’s skills lie in the business development and the finance and the operations – actually making it work."
Whether or not she has a meeting, Ella and Matt try to visit one of the delis every day. "I normally have one meal a day at one of the delis," she said. If she's eating breakfast at home, it's usually something like peanut butter on toast. This morning, she grabs a couple of brownies to go.
"When we first opened the Seymour Place deli we were there 18 hours a day serving food, cleaning loos, and doing everything we possibly could to get a granular knowledge of the business," Matt said. "I don’t think you can ask someone to do something you’re not willing to do yourself."
Ella has just under one million followers on Instagram, and she tries to talk to all of them. "Every morning on my way to whatever I’m doing first, I sit and go through the hashtag #DeliciouslyElla on Instagram," she said.
As we head to her next meeting of the day, she shows me the most recent posts. "This morning I did it on my way in. I’ve already liked every single one of them."
"I’m on my phone 24/7 replying to every Instagram comment and message to try and understand how people are seeing us, and their questions and concerns."
She also uses her travel time to reply to the 250-300 emails she gets a day. "If you can keep firing it off throughout the day I find that 100 times easier," she said. "It’s pretty stressful otherwise."
Not all the messages she receives are positive. Parody Instagram account Deliciously Stella, operated by Bella Younger who mocks clean eating, has 140k followers.
Ella added: "You have to separate the negative into two categories – half of it is sensible, constructive things that has made us better. But half of the negative online is negative for the sake of being negative, and it’s important for us to remember it’s okay they don’t like us and sometimes there’s no point in engaging in that."
Next on the day's agenda is a visit to the Mae Festive Pop Up in London's Neal's Yard, the third Mae Deli location.
Ella said the brand has been interested in Neal's Yard for some time. She decided to try it out with a pop up serving festive treats like hot chocolate, mince pies, hot stews, brownies, and orange cake.
If all goes to plan, they will have a full-time lease on the spot from January, and will open a permanent spot in February.
"We're going to see how it works and whether it makes sense financially," Ella said.
Next, Ella and Matt headed to their design agency for a meeting to discuss the packaging of their new products — energy balls.
They launched three months ago in Whole Foods and became the retailer's most successful new product ever, according to Matt. Now in 1,500 stores including Waitrose, Starbucks, Holland & Barrett and WH Smith, they're about to launch two more flavours and are looking at expanding
Now in 1,500 stores including Waitrose, Starbucks, Holland & Barrett, and WH Smith, they're about to launch two more flavours and are looking at expanding the product to Europe and eventually the US and Canada.
"Ella has really strong followings in a lot of places, but particularly in Australia, Germany, and the US," Matt said.
The balls are made of four to six simple ingredients, and Deliciously Ella shares the recipes so they can be made at home.
"A lot of people say, aren’t you shooting yourselves in the foot by sharing the recipe? But let’s be honest, most people aren’t going to make it, because you’re busy and you get home from work late and leave early in the morning so you don’t have time to do everything," Ella said.
A nut-free ball and protein ball with slightly different packaging will launch next year. The team debated and discussed colours, illustrations and fonts.
"We’re now looking at doing a lot of new product development and have a range to release as soon as March next year outside of snacking," Matt said.
Ella added: "The free-from aisle is the most depressing place in the supermarket. We want to fill in that gap of easy, everyday items."
After the meeting, Ella and Matt head to their Bloomsbury office. "We got the office in March 2015, and it was meant for five people," Matt said.
There are currently 14 people in the office, and 65 to 70 working for the company in the delis, so the team are looking for a new space near Oxford Circus.
"We think by this time next year, we’ll have around 30 people in the office," Matt said.
The kitchen is well used. "We have to have a space where you can have a kitchen for recipe tasting, good light to take pictures, and of course desk space," Matt said.
Ella checks on the progress of Deliciously Ella's first ever email newsletter, which is about to be sent out.
They then sit down for a team meeting — an impressive spread of food included.
"We have a team meeting every Tuesday morning," Matt said. "Everyone works in the same office together."
At the end of the day, Ella and Matt call Earl's Court home. "We’re both from London, so we’re pretty attached to it," Ella said.
When she's not cooking, they like to eat out, which they do at least a couple of nights a week. Ella's favourite restaurants include The Barbury, Pachamama, Chicama, and a local Indian restaurant in Earl's Court called Noor Jahan.
"I like food with a lot of flavour — especially Middle Eastern and Indian Food," she said.
"The sister restaurant of The Barbury, Palomar, has been one of our favourite restaurants this year," Matt said. "That's where we had our second date."
The first date took place at Yotam Ottolenghi's restaurant Nopi. "Matt did a good job," Ella said. "Plain food is my worst nightmare."
Matt and Ella share their home with their cocker spaniel, Austin.
On the Friday we met, they were preparing for a weekend with their parents, but they tend to work weekends — the online world and the work at the delis never stops.
Ella said: "We have a Sunday night ritual of working for a few hours and clearing out the inbox or writing a blog post while watching X-Factor."
Despite the long hours, Ella finds time to do yoga — and sometimes gets the whole family involved.
However, she tries to make sure she doesn't push the lifestyle that works for her onto her friends and family.
"It’s important not to be preachy," she said. "Just because you like something doesn’t mean other people will."
