Tarte a l'Oignon

Making Tarte a l'Oignon Ahead

Keeps for 3 days in the fridge. Reheat at 160°C / 320°F for 15 minutes.

Making Tarte a l'Oignon

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1. Rub the cold butter into the flour. Mix in the egg yolk and water to a dough, wrap and chill for 20 minutes.

   Mark done Start 20 min timer

2. Heat the oven to 190°C / 375°F. Roll the pastry to fit a 24 cm tin, line with paper and beans and bake for 12 minutes. Remove the paper and beans and bake for 5 minutes.

   Mark done Start 12 min timer

3. While the case bakes, melt the butter with the oil, add the onions and half the salt, cover and cook over low heat for 10 minutes.

   Mark done Start 10 min timer

4. Uncover and cook for 25 minutes, stirring often, until deep golden. Add the wine and cook until it evaporates.

   Mark done Start 25 min timer

5. Beat the eggs with the cream, thyme and remaining salt. Reduce the oven to 180°C / 355°F.

   Mark done

6. Spread the onions in the case, pour over the egg mixture and bake for 40 minutes until set and golden.

   Mark done Start 40 min timer

Worth Knowing

• Cook the onions slowly until they are the colour of dark honey.
• Add a splash of wine or water if the onions start to catch.
• Blind bake the case so the base stays crisp.

Serving Ideas

Green salad · Cold cuts · Dry white wine

Ingredient Swaps

• In a sauce, full-fat crème fraîche can usually take the place of the double cream; single cream is thinner and more likely to split if it boils, so keep it below a simmer.
• A dry vermouth keeps for longer than an open bottle of white wine and is the closer swap than a random white left in the fridge; for an alcohol-free version, use the same amount of stock with a squeeze of lemon.

Quick Answers

Tarte a l'Oignon Nutrition

Per serving, calculated from the ingredient list with USDA FoodData Central figures (SR Legacy). A calculation, not a laboratory analysis: brands, cuts and how you measure change the real numbers. The calories include 1 g of alcohol a serving, which is not part of the protein, carbohydrate or fat. How the figures are worked out.