In an ovenproof frying pan, saute onion and garlic in olive oil until translucent and tender.
Add red bell pepper, chopped tomatoes and cilantro, and continue sauteeing until everything is tender.
In the meantime, in a small bowl, add the canned diced tomatoes, paprikas, cumin, salt, pepper, and water. Mix well.
Add half this mixture to the pan, and cook for a few minutes more.
Sprinkle the salmon with a tbsp or so of the hot paprika/cayenne, and rub it in the salmon.
Add the salmon, skin side down, and cook for about 10min, until salmon looks cooked through about half the thickness.
On top of the salmon, add the rest of the tomato-spice mixture (now nearly all the salmon should be in sauce), and continue to cook the salmon for a few minutes more - total around 10minutes.
Pour lemon juice over the salmon, cover the pan with a lid, and cook till salmon is ready, about 5min.
Remove cover and place pan in oven, and broil for around 7 minutes.
Enjoy! (Don't forget to have a cup of ice water near).