Tarte à l’Oignon Alsacienne (Alsatian Onion Tart with Bacon)

Pastry

• 200 g Plain flour
• 1 tsp Fine sea salt
• 125 g Unsalted butter, cold
• 45 ml Water, cold

Filling

• 3 large Yellow onion
• 150 g Bacon
• 20 g Unsalted butter
• ½ tsp Black pepper
• 1 pinch Whole nutmeg
• 3 Egg
• 250 g Crème fraiche

1. Tip the flour and salt into a bowl. Rub in the cold butter until it looks like fine breadcrumbs, then add the cold water and bring together into a smooth dough. Flatten into a disc and chill for 30 minutes.
2. Heat the oven to 190°C (375°F). Roll the pastry out on a lightly floured surface and line a tart tin, pressing it into the corners. Chill for 10 minutes while the oven heats.
3. Prick the base all over with a fork. Bake for 15 minutes until the base looks dry and is just starting to colour. Set aside while you make the filling.
4. Peel and thinly slice the onions. In a frying pan over medium-low heat, melt the butter, add the onions and a pinch of the pepper, and cook for 20 to 25 minutes, stirring often, until very soft and sweet but not browned. If they start to catch, lower the heat and add a splash of water.
5. In the same pan over medium heat, cook the bacon for 5 to 7 minutes until lightly golden and the fat has rendered. Stir the bacon into the onions, then spread the mixture evenly over the warm tart base.
6. Whisk the eggs with the crème fraiche, remaining pepper, and a fine grating of nutmeg. Pour the custard over the onion and bacon filling. Bake for 25 to 30 minutes until the custard is set with a slight wobble in the centre and the top is lightly golden.
7. Rest the tart for 10 minutes before slicing so the custard settles. Serve warm with a simple green salad.

Made this recipe? Rate it — a comment is optional.