In a small bowl whisk together cumin, coriander, cayenne pepper, 1/2 - 3/4 tsp salt (depending on how salty you like things) and 1/2 tsp black pepper. Dab both sides of salmon dry with paper towels, season both sides evenly with cumin mixture and lightly rub over salmon. Heat a (heavy) 12-inch non-stick skillet over medium-high heat. Add oil and once oil is shimmering add salmon (top side down first. Also leave space between fillets) and cook about 4 minutes, without moving, on the first side un