Sprinkle salmon fillets with onion, poppy seeds, sesame seeds, garlic flakes, salt and pepper. In a small skillet, heat EVOO, one turn of the pan. Place salmon skin-side down and cook for about 2-3 minutes. Flip and finish cooking another 2-3 minutes, until cooked to your desired doneness.
While salmon is cooking, mix sour cream with scallions in a small bowl.
Serve salmon with a dollop of sour cream and side salad of halved cherry tomatoes, watercress and sliced red onion dressed with lemon juice and EVOO.