For the shortcrust pastry, mix flour with salt and onion seeds in a bowl. Put the butter in small flakes in the bowl and crumble with your hands.
Pour Ländle milk into the flour mixture and quickly knead everything into a smooth dough. Leave to rest in the refrigerator for 30 minutes in cling film.
In the meantime, prepare the filling. Whisk the cream with the eggs and season with thyme, salt and pepper. Cut the leek into very fine rings and mix in.
Peel the carrot and cut into thin strips with a peeler. Preheat the oven to 200 °.
Roll out the dough to about 0.5cm thick and place in a smaller tart pan (about 20cm). (Possibly butter the mold beforehand) Pre-bake in the oven for 5 minutes. Then spread the cheese on the bottom and pour in the cream mixture.
Spread the peas and carrot strips and bake for about 25 minutes. The filling should be bush hammered and golden brown. If the quiche gets too dark, cover with aluminum foil towards the end of the baking time.