Classic French savory tart with bacon, onions, and custard filling in buttery pastry. Makes two thin crusts for ~22cm forms or one ~28cm.
Powdered sugar distributes more evenly than granulated sugar for better texture.
Add cold butter and mix by hand until mixture resembles breadcrumbs. Butter shouldn’t be too soft or dough will be difficult to work with.
Add egg yolks and knead by hand until uniform. You can use 1 whole egg instead, but yolks create more tender, crumbly texture.
Depending on egg size and flour properties, consistency may vary.
If dough is too crumbly and won’t form plastic mass, gradually add ice water one tablespoon at a time until dough comes together perfectly.
Knead until uniform and pliastic consistency. Form into ball, wrap in plastic wrap, and refrigerate for 30 minutes to rest and activate gluten.
Roll dough between two sheets of parchment paper. Line 22cm tart pan (or 28cm for single large quiche) with pastry, trim excess with knife.
Prick bottom all over with fork to prevent puffing. Alternatively, line with parchment and fill with dried beans or rice as weights.
Pre-bake at 200°C for 8-10 minutes. Remove from oven and cool.
Fry bacon in large skillet to render fat. Remove bacon and set aside.
Finely chop onion and fry in rendered bacon fat until caramelized. Add to bacon. Discard remaining fat.
In a large bowl, whisk eggs, then add milk, heavy cream, grated cheese, the bacon and onion mixture, salt, black pepper, paprika, and nutmeg.
Brush pre-baked pastry shell with egg white to seal. Pour in filling mixture.
Bake at 175°C for 50 minutes or until filling is set - test doneness by inserting knife in center, it should come out clean.
The egg white creates a barrier preventing soggy bottom crust.