Melt the butter in a cast-iron pan over medium-low heat. Add the thyme and rosemary, and let herbs cook for a minute just until they release their fragrance. Remove from the heat. Allow the thyme and rosemary to infuse in the butter for 20 minutes.
Add mustard, honey, salt and pepper to reserved butter. Mix well.
Add wild salmon to pan. Brush wild salmon with butter herb mixture. Add a few sprigs of rosemary and thyme to butter mixture.
If using a grill, prepare charcoal grill by heating the coals until they’re pale grey and glowing orange, about 20 minutes. Move hot coals to one side of the grill, and place the cast-iron pan with fish on the opposite side.
If cooking on stovetop, bring cast iron pan to medium heat.
Using a spoon, continuously spoon butter and herb mixture on top of the wild salmon, bathing the fish in it.
Continue cooking and basting until the fish flakes when poked in the middle and it is cooked to your liking, about 8-10 minutes.
Serve sprigs of fresh herbs on top, and wedges of fresh lemon.