Vegan onion tart

Ingredients

• 250 gplain flour
• 120 gvegan butter or cold margarine
• 1/2 tspsalt
• 2 tbsp (approx.)ice-cold water
• 700 gonions
• 3 tbspolive oil
• 100 gseitan bacon or smoked tofu
• 150 gvegan cream
• 150 gvegan sour cream
• 30 gcornflour
• 1 1/2 tspsalt, to taste
• 2 pinchespepper
• 1 pinchnutmeg
• 1 pinchturmeric (optional, for colour)
• 1/4 tsppaprika
• 1 tbspcaraway seeds (optional)

Instructions

1. 1

   Make the pastry

   Put the flour, salt, cold vegan butter cut into small pieces and ice water in a bowl. Mix first with dough hooks, then by hand, working the mixture from crumbs into a smooth shortcrust pastry. If it stays very dry, add a little more ice water.

2. 2

   Chill the pastry

   Shape the pastry into a large ball and divide it, taking a generous third for the edge and flattening it slightly; flatten the remaining two thirds too. Wrap both portions or place them in a lidded container and chill for at least 30 minutes, or make the pastry the day before.

3. 3

   Cook the onions

   Peel the onions and cut them into fine rings or dice. Heat 2 tbsp of the oil in a large frying pan and cook the onions over a medium heat for about 5 minutes, until translucent, then remove them from the pan. Briefly fry the seitan bacon or finely diced smoked tofu in the remaining oil.

4. 4

   Mix the filling

   Stir together the vegan cream, vegan sour cream, cornflour and spices until well combined. Add this mixture and the vegan bacon to the prepared onions, mix everything thoroughly and adjust the seasoning to taste.

5. 5

   Line the tin

   Take the pastry out of the fridge and let it come up slightly towards room temperature. Heat the oven to 180°C, conventional top and bottom heat. Line the base of a 26 cm springform tin with baking paper. On a lightly floured surface, or preferably between sheets of cling film, roll out the larger portion to fit the tin and lay it in as the base. Roll the remaining pastry into 1–4 long ropes, place them around the edge, press them onto the base with your fingers and build up a rim about 3 cm high.

6. 6

   Fill and bake

   Spread the onion mixture over the pastry base and level it. If the pastry sticks up too far around the edges, gently press it down towards the filling with your fingers. Bake the tart for about 45 minutes. It is good hot or lukewarm, and can also be chilled and reheated in the oven.

What is vegan onion tart?

Onion tart is a savoury bake built around a pastry case and a rich onion filling. This version uses a shortcrust base and a creamy, seasoned mixture, while vegan cream, sour cream and smoky seitan or tofu replace the usual animal-based ingredients.

Onion tarts are associated with German-speaking home cooking, though similar savoury onion bakes appear in neighbouring regions too. Here, the combination of slowly softened onions and a crisp pastry case gives the familiar, hearty character.

Nutrition and macros by portion

The nutrition label shows one serving as written: 3400 calories, 55g protein, 330g carbs, 205g fat.

The flour and onions provide most of the carbohydrates, while vegan butter, olive oil, vegan cream and sour cream contribute much of the fat. Protein comes mainly from the flour and the seitan bacon or smoked tofu; the amount varies with the products used. The recipe lists one serving for a 26 cm tart, so the estimate treats the whole tart as one serving; serve it with salad or vegetables for a more balanced plate.

A tender shortcrust base

Cold fat: keep the vegan butter or margarine cold and cut it into small pieces before mixing. This helps the pastry stay short and crumbly rather than turning elastic.

Ice water: add only enough to bring the dough together. If it still looks dry after mixing, add a little more a few drops at a time.

Soften the onions gently

Onion cut: fine rings or a small dice both work; the important thing is to keep the pieces fairly even so they soften at a similar rate. Cook them over medium heat for about 5 minutes, until translucent, rather than trying to brown them.

Smoky element: seitan bacon or smoked tofu adds a savoury contrast to the sweet, soft onions. Fry it briefly in the remaining oil before combining it with the filling.

Get the filling to set

Cornflour: mix it thoroughly with the vegan cream and sour cream so it is evenly distributed through the filling. It helps the mixture firm up as the tart bakes.

Seasoning: taste the onion mixture before it goes into the pastry and adjust the salt to suit your ingredients. Nutmeg, pepper and paprika round out the creamy filling, while turmeric is optional for colour.

Shape and bake the tart

Pastry portions: use the larger two-thirds for the base and the remaining third for the sides. Press the joins together where the edge meets the base, aiming for a rim about 3 cm high.

Doneness: bake at 180°C for about 45 minutes. The filling should look set and the pastry should be cooked through; let the tart stand briefly if you want cleaner slices.

Serving and timing

This is a substantial tart with a creamy filling and pastry, so serve it with a crisp green salad or lightly dressed vegetables for contrast. It can be eaten hot or lukewarm, as the recipe suggests.

The stated total time is 80 minutes, including at least 30 minutes of chilling and about 45 minutes of baking. Making the pastry the day before is also an option if you want to split the preparation.

Recipe notes & tips

• Chill the pastry for at least 30 minutes so it is easier to handle.
• Add extra ice water sparingly if the dough remains crumbly and dry.
• Cut the onions into evenly sized rings or pieces for consistent softening.
• Mix the cornflour thoroughly into the creamy ingredients to avoid lumps.
• Use baking paper on the base of the springform tin to make removal easier.
• Let the tart stand briefly after baking if you want neater slices.

Variations

• Use smoked tofu: finely dice it and briefly fry it in the remaining oil.
• Add caraway: include the optional tablespoon for a distinctive savoury note.
• Boost the colour: add the optional pinch of turmeric to the creamy mixture.
• Change the paprika: use smoked paprika for a deeper smoky flavour.
• Adjust the onions: cut them into rings for a more visible onion texture.

Common mistakes to avoid

• Warm pastry: keep the butter or margarine cold and chill the dough before rolling.
• Dry dough: add a little more ice water rather than forcing the crumbs together.
• Overcooked onions: remove them after about 5 minutes, once translucent, so they do not brown heavily.
• Lumpy filling: stir the cornflour into the vegan cream and sour cream until smooth before adding it.
• Thin pastry edge: press the pastry ropes firmly onto the base and build the rim to about 3 cm.
• Cutting too soon: allow the filling to settle briefly after baking for easier slicing.

How to store

Once cool, cover and refrigerate the tart for up to 3 days. Reheat portions in the oven until warmed through; the recipe also notes that it can be chilled and reheated in the oven.

Frequently asked questions