Prepare a shortcrust pastry with the flour, butter, water and salt and then place it in a greased springform pan (24 cm).
Bake the dough blind in the preheated oven at 200 ° C for about 10 minutes.
Chop the onion and fold it into the thawed kale. Season with salt and pepper. Fold the grated cheddar cheese and chopped walnuts into the cabbage and place everything on the pre-baked quiche batter.
For the topping, stir together the eggs, cream and milk and pour over the quiche.
Put the quiche back in the oven and bake until golden for about 30 minutes.