Veg Chef Daniel Acevedo on Ultimate Veggie Burgers

NewImage.jpgDaniel Acevedo (pictured with his partner, Sarah Wasserman), is head chef at Mildred’s vegetarian restaurant, famous for, among other things, its constantly changing (and always vegan) “burger of the day”.

Mildred’s beetroot burger remains one of the best veggie burgers I’ve ever had, and their kidney bean and olive burger was a close second. I wrote about these elusive burgers last year when I described my quest for the ultimate veggie burger and asked: just what are these burgers made of?

Serious about my quest, I went straight to the source, Daniel himself, and spoke to him about how they make the burgers at Mildred’s. Daniel was kind enough to entertain my burger fancies, and even shared a mouth-watering recipe for their popular beetroot and fennel burgers. Turns out, the secret is in the “Sosmix”.

Mildred's Awesome Veggie Burger

The burgers at Mildred’s rock my world. Are they your own recipe?

Our burgers have been on the menu about 15 years, and I’ve been in the kitchen about six. We have a standard recipe we follow but we change the vegetables and ingredients to flavour them differently. The burger mix changes every two or three days.

What are the fundamental ingredients that go into a cohesive burger?

It begins with Sosmix, the main binder of our burgers, which is a dehydrated soy mince that you can buy at shops like Whole Foods and some grocery stores. There are a few different brands but they’re all fairly similar.

To this we add vegetables, fresh herbs, dried herbs, tinned tomato or water, and a bit of gram (chickpea) flour to hold it together. The vegetables and herbs vary depending on what flavor we’re after. For example, today I made a red pepper, caper and courgette burger, to which I added parsley, oregano and black pepper.

Finally, we add chopped tinned tomatoes or the equivalent amount of water to bring it all together. The amount depends on how much water the sosmix is going to absorb and the types of vegetables we’re using.

I’ve seen bean burgers on the menu – where do those fit in?

We use the same formula and treat beans like one of the vegetables. But you must remember, cooked beans have lots of liquid so you won’t need to add as much water or tomatoes to the mix.

It seems like there’s an art form to achieving the perfect moisture balance – how do you know when the burgers are just right?

With the tomatoes and water, it’s not something you can really measure – start with a little and add it as you need it. And if you are adding beans or juicy carrots, add less liquid.

Mildred's Vegetarian Restaurant

What about texture? Do you choose certain ingredients for texture?

We generally choose a theme and base our burger around that. So, if it’s Italian then we’ll add black olive and basil. If it’s Mexican, spices. Asian, coriander. Sometimes we put seeds and nuts in the burger but not too often because we deal with a lot of nut allergies.

Do you have any advice for people who want to make a veggie burger at home?

The main thing is not to rush the process. If you’re using our method, you really need to left the burgers sit 30-40 minutes. Then you need to test the mixture. You want a mixture that you can grab in your hands and form into a burger, but doesn’t leave your hand messy. It should be dry enough to mold into a burger shape, but not so dry it crumbles apart when you cook it. It’s an in between thing. Trial and error. Be patient with it.

Mildred's Vegetarian Restaurant

Check out Mildred’s blog to read about Daniel’s recipes and food experiment with his comrade Sarah Wasserman. And if you’re in London, book a table at Mildred’s for lunch or dinner. You won’t be disappointed.

Mildred’s Beetroot, Fennel & Dill Burgers

Mildreds' Beetroot and Fennel Burger

Sosmix is a dehydrated soy mince that you use for making veggie sausages and can buy in health food shops. A similar product is Granose Meat Free Sausage Mix. You might also get away with using TVP and breadcrumbs, in which case, be sure to add a bit of salt to your mixture! Many thanks to Daniel Acevedo for the recipe!


  • 2 med beetroot, peeled and grated
  • 1/2 bunch dill, chopped
  • 1/2 Tbsp fennel seeds
  • 1 small fennel bulb, washed and finely diced
  • 400-500ml water
  • 1 litre Sosmix


  1. Saute the diced fennel bulb with some olive oil until tender; add the beetroot and continue cooking for a couple minutes until the beetroot is cooked but still has texture (al dente).
  2. Mix the sauteed vegetables with the remaining ingredients. Let the mixture rest for at least 40 minutes, then form into burger patties.
  3. To cook, heat non-stick fry pan on lowest heat, add a touch of oil and fry burger on each side for 4-6 min until golden brown.

8 thoughts on “Veg Chef Daniel Acevedo on Ultimate Veggie Burgers

  1. Jes

    Hmmm that Sosmix sounds really interesting but I can't think of anything like it over here in the states. I'm loving the photos of the restaurant the most though! So cute and vibrant, but in an understated, comfortable way. I feel like veg places here over do it with color. Though the beet burger definitely adds a splash of color!

  2. Monica

    I'll see if I can dig up a similar product in the states… maybe Daniel can help. Rebecka, if you try the recipe, do let us know how it turns out!

  3. Gloria

    I am almost in tears reading this post. That may seem like a rather extreme reaction to a post on veggie burgers, but I worked in Soho when Mildreds first opened in Greek Street and went there regularly until I left London 5 years ago. Going there at the weekend to read the paper and eat the burger with chunky fries etc was just my favourite thing and one of the few things I miss about the capital. I have been yearning to develop a recipe to match some of the many versions I have eaten at Mildreds. Once I had an apricot chutney on my burger and I've been trying to replicate it ever since. Thanks for this information.

  4. Monica

    You're very welcome, Gloria, and so touching to read your heartfelt story about working at Mildred's. I can totally imagine the scene you describe – it's such a great place for chilling out with a burger. You may wish to listen to my phone call with Daniel, where he talks about veggie burger technique – might give you some pointers:

    Interview with Daniel Acevedo, Mildred's Head Chef

  5. Gloria

    Thanks for that. It was really interesting. Must admit when I heard an important ingredient in the burgers was sosmix I was quite shocked. I've been vegetarian since early 70s and never use those meat substitute type ingredients ever. Rarely even eat tufu, which often people think is a vegetarian staple. I'm going to try making some Mildred burgers, see if they match my memory of them, see what sosmix contains and see what you could use instead if that isn't what I want.
    Recently went to a 50s airstream diner as a treat! Of course meat burgers are their speciality but they'll do a veggie burger to cater for veggies. But the veggie burger was just totally lifeless and dull. Not at all reaching for the best that it could be, just something to appease the odd vegetarian that calls by. A local speciality butcher does a sausage Saturday event each month. He doesn't do a veggie option, why should he? It isn't his area of expertise. I'm tempted to set up a 'battle of the burgers' stall opposite him with homemade rhubarb ketchup, chutneys and relishes!


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