Peel pumpkin and potatoes. Prick out balls from the potatoes, peel and dice pumpkin. Boil both separately in salted water until al dente. Froth up butter, toss vegetables and season with salt, pepper and nutmeg.
Season salmon with salt and pepper. Heat oil in a pan and fry the fish on both sides. Remove from pan and keep warm. Toss butter in frying residue and stir in herbs.
Serve the salmon with sauce and vegetables.