Vegan onion tart: making my signature dish plant-based

The Vegan Society recently congratulated a number of Scottish SMPs for issuing a motion to support the Society’s Vegan for the World campaign. Part of the campaign is a challenge for all of us to go vegan for a week for the environment. I’m not vegan but most of what I eat and cook is. I’ve learned to reach for new ingredients to adapt some of my favourite recipes. Like my signature onion flan.

It looks a little scorched but those dark bits just add extra caramelisation. No, honestly.

It looks a little scorched but those dark bits just add extra caramelisation. No, honestly.

When I was a teenager I developed an onion and leek flan loosely based on a quiche recipe. It involved 3 large leeks and several onions – finely sliced and softened in butter, three eggs, 200 ml milk and a couple of hundred grams of grated mature cheese in a pastry case. It was deep and delicious and I have served it at all kinds of occasions, from picnics to dinner parties. For a long time, it was my signature dish.

Now I live with a dairy-intolerant vegetarian who also responds very badly to soft-set egg. My pride and joy onion flan would make him very uncomfortable indeed. I miss it’s onionness, however, the savoury umami flavours of caramelized onions, the golden, set top, the pure comfort that flan represented to me.

The other week I decided to make a vegan version using silken tofu. I’d never used tofu in this way before and was a little nervous that it wouldn’t actually set. But it did. I got a lovely soft set that didn’t rubber up when I forgot it in the oven for a few extra minutes, like egg can.

I took my new-style flan to a party and it went down well. A couple of days later I made another version, this time without pastry (hurra for silicon bakeware). I played with nutritional yeast and fermented tofu to get some of the umami notes that cheese brought to the original. I didn’t get the full cheese effect but they did add richness.

It’s a very different dish from the one I served when I was younger: it’s softer since there’s no cheese or egg, and it’s shallower but tastes great and is easy to make. I’ll continue making it for all kinds of occasions: the onion sings.

Onion flan
Preparation time
Cooking time
Total time
This easy onion flan can be made with or without pastry. The recipe is for the filling: if you want pastry, make and blind bake this separately. A Boston pastry (flour, oil and water) works well, especially if you use rye or buckwheat flour as well as wheat.
Recipe type: Flan
Cuisine: Vegan
Serves: 4-8
  • 500 grm onion
  • 500 grm leeks
  • 2 tbsp olive oil
  • 400 grm silken tofu (one block)
  • 100 ml soya milk
  • 2 tbsp nutritional yeast (optional)
  • A good shake of nutmeg (optional)
  • Chilli flakes to taste (optional)
  • 1-2 cubes fermented tofu (optional)
  • 1 tbsp soy sauce
  • Salt and pepper
  1. Pre-heat the oven to 200C (180C fan).
  2. Trim and finely slice the onions and leeks.
  3. Heat the iol in a pan and add the onions and leeks.
  4. Cook until caramelised, 30-40 minutes depending on the heat. You want ot brown but not burn or dry out the veg.
  5. In a separate bowl or a stick-blender mixer attachment, mix tofu, milk and flavourings until smooth.
  6. When the onions are done, mix the tofu mixture into them.
  7. If using a pastry case, pour the mixture into the case and even out the top. Else pour into a well-greased or non-stick case.
  8. Cook for 30-40 minutes, or until set and golden brown on top. The longer time gives a darker more caramelised top.
  9. Remove from oven and let rest for a few minutes.
  10. Serve with salad and, if your diners are hungry, bread on the side.

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About Caroline von Schmalensee

Cooking, eating and drinking is fun as well as necessary. I do food for fun and I write for a living. Good food makes the world a more delicious and satisfying place. Good writing, meanwhile, can make the world a less confusing place.

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