Cut the fillet into 4 pieces. Fry in hot oil all around for about 5 minutes. Season with salt and pepper and take out. Preheat oven (electric cooker: 225 °C/circulating air: 200 °C/gas: see manufacturer)
Add cream and frozen Brussels sprouts, bring to the boil. Cover and cook for about 10 minutes.
Put the Brussels sprouts together with sauce and fillet in an ovenproof dish. Crumble bread over it, sprinkle with cheese. Spread butter in flakes on top. Bake in the oven for about 10 minutes. Sprinkle with parsley.