In a small mixing bowl, combine the blackened seasoning ingredients.
If you have a large piece of salmon, cut the fish into 4 equal pieces of about 6 ounces each.
Pat dry the salmon with paper towels and then season the fish liberally on both sides with the blackened seasoning (you can use as much or as little seasoning as you wish). Lightly pat the spices to adhere as needed.
Heat a large heavy bottom pan or cast-iron skillet over medium-high heat. Once hot, add the oil and the butter.
Remove the hot skillet from the burner by sliding it to the side. Add the salmon fillets, one at a time in a single layer, flesh side down. Return the skillet to the heat and cook for about 2-3 minutes. Using a spatula, flip the salmon to the other side. If the salmon has skin, cook it until the skin gets crispy, about 4-5 minutes. If the salmon is skinless, cook for about 2 minutes or until the fish is cooked through and flakes easily (time depends on the thickness of the salmon fillet).
Remove from the heat and arrange the salmon on a platter. Serve topped with the salad and with lemon wedges.