In a glass baking dish, combine the garlic, white wine, lemon juice, soy sauce, olive oil, poultry seasoning, salt, and pepper. Mix just to blend. Place mahi mahi steaks into the marinade, and refrigerate for 1 hour, turning frequently.

Preheat an outdoor grill for high heat and lightly oil the grate.

Grill mahi mahi steaks for 5 to 6 minutes on each side. Cut 4 lemon slices and grill, about 3 minutes per side. Garnish mahi mahi with chopped parsley and lemon slices.