In a small bowl, mix together the creamy mayonnaise, salsa, Dijon mustard, and garlic powder. The resulting spread will add flavor and moisture to your sandwich.

Lay four slices of sourdough bread on a clean surface. Spread a generous layer of the mayonnaise mixture on each slice. For that cheesy goodness, add one slice of pepper Jack cheese, followed by the turkey slices, a sprinkling of chopped green onions, and another slice of cheese on top. Cap it off with another slice of sourdough.

Spread about a tablespoon of butter on the outer sides of each sandwich. This will ensure that the bread gets nice and golden when grilled.

Place your sandwich on a skillet over medium heat. Cook for about three to four minutes on each side, or until the bread is golden brown and the cheese has melted. Adjust the heat as necessary. You want it crispy, but you don’t want to burn it.

Once it's all beautifully browned and the cheese is oozing, remove it from the heat. Let it cool for a minute, then slice it in half or quarters. Serve it hot with your favorite dipping sauce.