Season cod fillets with pepper and 1 tbsp. juice of one lemon. Spread each side thinly with the two types of mustard. Place on a baking sheet, drizzle with vermouth, fish stock and olive oil. Cover and leave to cool.
Preheat oven to 160 degrees.
2. make mustard seeds in boiling hot salted water 1 minute, quench and drain. Finely dice shallots. of the cress bunch, chop the bottom half of the stalk. Coarsely chop the cress.
Peel the horseradish, grate finely and mix with the horseradish from the jar. Boil vegetable stock with 500 ml salted water.
3. Heat 30 g butter and oil. Sauté shallots in it until soft without color.
Add long grain rice and mustard seeds, steam briefly. Extinguish with white wine.
Add about ¼ of the stock, fold in the risotto rice and cook for 20-25 minutes. Add the remaining hot stock little by little. Season the risotto with salt, pepper and nutmeg. 4.
In the meantime, cook the fish fillets in the oven on the lowest rack at 160 degrees for 12-15 minutes (gas 1-2, convection oven 12 minutes). Remove the fish from the stove and roughly shred. Collect the stock.
Add watercress, fish stock and remaining butter to risotto, season with remaining juice of one lemon. Arrange on plates, evenly distribute the pieces of fish on top and bring to the table with the horseradish.