Divide the cauliflower into not too large florets, peel the potatoes and cut into approx. 1 cm cubes. Boil both in salted water for about 8-10 minutes and fill in a greased casserole dish.
Shape the minced meat into small balls and brown them in a pan with a little oil, also put them in the baking dish.
Mix the hollandaise with the egg yolks and mustard, whip the cream and add. Season with salt and pepper and pour over cauliflower, potatoes and meatballs.
Bake in the preheated oven at 180 ° convection or 200 ° top and bottom heat for about 20-25 minutes.