Fillet your kokanee if you haven't already done so. Then, score the skin with some light cuts, just penetrating the skin.
Season your kokanee fillets with the Garlic Salt, Rosemary, and Old Bay Seasoning
Preheat your pan on a medium high heat. You want the pan hot enough for the salmon to sizzle and create a sear when you put it in the pan in the next step. Once the pan is preheated, add you olive oil to the pan. Adding the oil to the cold pan can burn the oil.
Lay your salmon into the pan, skin side down. Add your herbs to the pan as well. Cook for 2 minutes.
Gently flip your salmon, adding the butter to the pan, then cook for another 2 minutes.
Gently flip your salmon back to skin side down. Reduce heat to low and cover. Cook for another 2-8 minutes, depending on how thick your fillets are.
With about 1 minute remaining, add the lemon juice onto the fish
Remove from heat and serve hot.