Cut fillet into portion pieces, salt, pepper, sprinkle with lemon juice, leave for 10 minutes, then fry in butter until golden crust.

Sautee flour, add beer, bring the sauce to boil.

Chop onion, slice mushrooms, mix with greens and fry in butter for 5 minutes. Put a half of mushroom mass in greased mold, scatter over the fish, then put the remaining mushroom mass. Pour with prepared sauce, season with breadcrumbs, sprinkle with melted butter.

Bake for 40 minutes over 390°F.

Serve the baking with cooked potatoes, top with chopped spring onion.