Lay 2-6 ounce grouper fillets on a large enough piece of aluminum foil. Sprinkle 2 tsp Italian herb seasoning blend over the grouper and drizzle each fillet with olive oil and fresh lemon juice. Crimp the foil tightly into a packet. Heat the grill to medium heat and place the foil packet on the grill grates. Grill for 10 to 12 minutes. Remove the foil packet from the grill and wait one minute before opening. The fish should be flaky and firm.