Mix cauliflower, onion and mushroom in blender/thermomix until fine and combined. Slice courgettes and potatoes and keep separate.

Add eggs and milk and blend again until a little bit frothy

Put oil and butter over medium heat in frying pan. Put potato sliced in and egg mixture on top. Cover with cheese and place courgette slices on top.

Put lid on pan and cook until mixture can be lifted slightly and still holds and looks brown on the bottom. Then put pan under high grill until top is brown.