1-First, thaw the spinach and squeeze out the excess water; this gives you about 1 cup before squeezing and 1/2 cup after, helping keep the filling from getting too wet.

2-Next, drain and chop the artichoke hearts into small, bite-sized pieces for even distribution.

3-In a large bowl, combine the spinach, chopped artichokes, 1 cup shredded mozzarella, 2 tablespoons grated Parmesan, 2 tablespoons mayonnaise, 1/8 teaspoon garlic powder, 1/8 teaspoon crushed red pepper if you like some heat, 1/8 teaspoon salt, and freshly cracked black pepper to taste, mixing everything until it’s evenly blended.

4-If you’re not using focaccia, spread a little of the 2 teaspoons butter on each bread slice for that extra crisp.

5-Assemble the sandwich by placing about 1 cup of the filling between two slices of bread, making sure the buttered sides face out.

6-Heat a skillet over medium-low heat and cook the sandwiches until they’re golden brown and the filling is fully melted, which takes about 5 minutes per side.