Preparation: In a bowl, whisk together olive oil, lemon juice, salt, pepper, garlic, dill, and parsley to create the marinade.
Marinate: Place the bonito fillets in a dish and pour the marinade over them. Ensure both sides are coated. Cover and let sit in the refrigerator for 30 minutes.
Preheat Grill: Heat your grill to a medium-high temperature.
Grill: Remove the fillets from the marinade and place them on the grill. Cook for 3-5 minutes on each side or until the fish flakes easily with a fork but remains moist inside.
Serve: Transfer the grilled bonito onto plates and garnish with extra herbs or lemon slices if desired.