In a small bowl, combine softened butter, grated Parmesan cheese, and garlic powder. Mix well until creamy and fully blended. Spread the mixture generously on one side of each slice of your chosen bread.

Take two slices of the prepared bread and place them butter-side down. Layer your choice of assorted cheeses, followed by slices of meats like turkey, then add another layer of cheese. Top with the second slice of bread, ensuring the buttered sides face out.

Heat a nonstick skillet over low heat. Place your assembled sandwich in the skillet and grill for about 5–6 minutes until the bottom is golden brown and crispy. Flip halfway through grilling.

While the sandwich is toasting, combine mayonnaise, red grape juice vinegar, remaining Parmesan, garlic powder, Italian seasoning, and cracked pepper in a bowl. Adjust seasoning based on your personal preference.

Fold in the shredded lettuce, sliced red onions, and banana peppers into the salad dressing until everything is lightly coated.

Once the sandwich is perfectly toasted, carefully open it up. Spoon a generous amount of the salad mixture onto one side, close it up, and slice the sandwich in half.