To make a grilled cheese sandwich more interesting or have gourmet grilled cheese energy try mixing up the fillings. Use pizza toppings, different meats, sauces, cheeses, and vegetables. To make a grilled cheese spicy add sriracha or chili paste like sambal oelek inside your sandwich. Try mixing a chili paste with mayonnaise for a spicy sauce to spread inside or outside your sandwich or even to dip in like ketchup.