For the bouillon potatoes, clean, wash and cut the peppers into strips. Peel, wash and slice the potatoes. Wash the rosemary, shake dry and pluck the needles.
Place the potatoes, rosemary, herb butter, stock and 150 ml water in a wide saucepan. Bring to the boil and simmer covered for about 20 minutes. Add peas and peppers after about 15 minutes and cook.
For the salmon, wash the fish, dab dry and cut into about 8 pieces. Season with salt and pepper. Heat oil in a pan. Brown the salmon on each side. Take it out and put it on a baking tray.
Mix the whole mustard and breadcrumbs. Spread the salmon with the mixture and gratinate under the preheated grill of the oven for 3-4 minutes.
Season the potatoes and vegetables with salt and pepper. Arrange everything.