This sweet onion quiche comes from 14th C. England.
(Ember days were three days of penance in each quarter of the liturgical calendar during which Catholics were instructed to abstain from eating meat and devote themselves to prayer.)
Forme of Cury, Master Cooks of King Richard II, c. 1390:
Tart in ymbre day. Take and perboile oynouns & erbis & presse out þe water & hewe hem smale. Take grene chese & bray it in a morter, and temper it vp with ayren. Do þerto butter, safroun & salt, & raisouns corauns, & a litel sugar with powdour douce, & bake it in a trap, & serue it forth.
Filling: 2 medium onions, 1 cup raisins (I used ½ cup currants and ½ cup golden raisins), 1 cup mild cheese (I used ¾ cup toma piemontese and ¼ cup provolone), 5 eggs, 1 Tbsp sugar, minced herbs (I used parsley, tarragon, basil), 1 tsp sweet spices (I used cinnamon, ginger, and nutmeg), 1 Tbsp butter, ½ gram saffron.
Allow ground saffron to bloom in a small dish of melted butter.
Quarter onions and cook in a covered pan with a half inch of water until softened. Drain onions and chop them with herbs.
Grate the cheeses, beat the eggs, and combine with other filling ingredients.
Crust: 1 ½ cups flour, ¼ lb butter, ½ tsp sugar, pinch salt, 3/8 cup water (plus an optional ½ tsp vinegar).
Combine flour, salt and sugar. Use a pastry cutter or food processor to cut in the butter until it is reduced to pea-sized lumps. Add the water and stir until a dough forms, but do not over-kneed it. Press into a flattened ball and cover snugly in plastic wrap. Refrigerate for at least 15 minutes.
Roll out the crust using a floured surface and rolling pin, then transfer to a pie plate.
Add the fillings and bake at 350° until set, around 45 minutes.
• Ember Day Tart at medievalcookery.com