Rub dry ingredients and butter together till it resembles bread crumbs. Add egg and water and mix until combined. Cover and refrigerate for 30 mins before using. Blind bake pastry case at 170°C until lightly golden.
Mix all three ingredients together. Pour mix over your favourite fillings – diced onion, grated cheese, bacon, tomato, herbs etc. Bake 150°C until egg mixture sets, around 35 to 45 mins.