Sort the spinach, wash and drain. Wash, clean and slice the mushrooms. Wash fish, dab dry and cut into pieces. Peel and finely chop the onion. Wash lemon, cut off 2 slices, squeeze the rest.
Bring 1/8 litre of water, cream, onion, lemon slices, bay leaf, some salt and pepper to the boil. Let the fish simmer for about 8 minutes. Sauté mushrooms in hot fat. Add spinach and steam briefly.
Keep the fish fillet warm. Bring sauce stock to the boil, stir in sauce thickener and bring to the boil again. Season with salt, pepper and lemon juice. Chop chives finely and stir into the sauce. Dill potatoes taste good with it.