Heat the oil in a large pan and add the peppers, onion and potatoes. Cook, stirring regularly for 5-8 mins until golden. Then add the paprika, garlic, thyme and tomatoes. Bring to the boil, stir and cover, then turn down heat and simmer for 12 mins. Add a splash of water if the sauce becomes too thick.
Season the stew and lay the salmon on top, skin side down. Place the lid back on and simmer for another 8 mins until the salmon is cooked through. Scatter with parsley, if you like, and serve.