This recipe is perfect for a delicious and healthy dinner. Start by marinating the Kanpachi fillets in a mixture of lemon juice, olive oil, garlic, salt, and pepper. Let the fish marinate for at least 30 minutes to allow the flavors to penetrate. Preheat your grill to medium-high heat and lightly oil the grates. Place the marinated Kanpachi fillets on the grill and cook for about 4-5 minutes per side, or until the fish is opaque and flakes easily with a fork. While the fish is grilling, prepare the lemon butter sauce by melting butter in a saucepan and adding lemon juice, minced garlic, and a pinch of salt. Cook the sauce for a few minutes until it thickens slightly. Serve the grilled Kanpachi fillets with the lemon butter sauce drizzled on top. This dish pairs well with steamed vegetables and a side of rice or quinoa.