Slice potatoes and cabbage. Drizzle half the olive oil over the potatoes and add salt and pepper.
Roast in the oven for 20 minutes then add the cabbage and the cod fillet. Drizzle the remaining olive oil over the cod and add salt and optional spices. Bake in that ol’ oven thingy for an additional 10 minutes.
Mix the quark, lemon juice, salt and optional spices and you’re away.