Clean the peppers and cut into pieces, finely dice the onions. Season everything with salt, pepper and thyme and sauté for approx. 5 minutes. Drizzle the cod with lemon juice and season with salt and pepper. Mix the sour cream with the milk and paprika powder.
Put the pepper / onion mixture in a baking dish, put the fish on top and pour the sour cream / milk mixture over it.
Then cook the whole thing in a preheated oven at 200 ° C for approx. 15-20 minutes.