Prepare the Marinade: Combine red miso, white miso, black soy, ginger, garlic, lemongrass, rice vinegar, lemon juice, and honey in a bowl. Whisk together until well blended.

Marinate the Salmon: Place the Coho salmon side in a suitable dish or a resealable bag. Pour the marinade over the salmon, ensuring it is evenly coated. Let the salmon marinate, preferably in the refrigerator, for an optimal flavor infusion.

Preheat the Grill: Preheat your grill to a medium-high temperature in preparation for cooking the salmon.

Prepare Salmon for Grilling: Remove the salmon from the marinade and shake off any excess. Place thin slices of lemon on top of the salmon.

Grill the Salmon: Place the salmon on the grill, skin side down. Grill until the internal temperature reaches 135°F. This temperature ensures that the salmon will carry over cook to an ideal 145°F, keeping it moist and flaky.

Serve: Once cooked to the desired temperature, remove the salmon from the grill and let it rest for a few minutes before serving.