Peel the potatoes and cut into wedges. Peel the carrots, cut the spring onions and mushrooms into pieces. Cut 2 slices from the lemon and squeeze the rest.
Grease a baking dish with the margarine, add the potatoes and vegetables. Pour the hot vegetable stock over the vegetables and season with pepper.
Wash and pat dry the salmon fillet and season with salt and pepper. Place on the vegetables and drizzle with the lemon juice.
Close the baking dish with aluminum foil and stew in the oven (convection 175 ° C, electric stove 200 ° C) for about 35 minutes. Garnish with dill and lemon wedges.