Start by gathering all your ingredients on a clean workspace. Lay out your slices of artisan sourdough bread, cheddar, and provolone cheese, and have your butter and garlic salt ready to go.
Spread a generous amount of butter on one side of each slice of bread. Make sure to cover the surface evenly for that perfect golden crust. Sprinkle a pinch of garlic salt on the buttered side for added flavor.
On the unbuttered side of four slices of bread, layer two slices of cheddar and two slices of provolone. Ensure that the cheese is spread out evenly to create a deliciously melty center.
Place the remaining four slices of bread on top of your cheese layers, with the buttered side facing out. This forms a beautiful sandwich that’s ready to hit the skillet.
Preheat your non-stick skillet over medium heat. Once hot, carefully place the assembled sandwiches into the skillet. You may need to cook in batches depending on the size of your skillet.
Cook the sandwiches for about 4-5 minutes on one side, or until they are golden brown. Flip the sandwiches carefully with your spatula and cook for another 4-5 minutes on the other side, ensuring the cheese is melted and the bread is crispy.
Once both sides are perfectly toasted and the cheese is oozy, remove the sandwiches from the skillet. Let them rest for a minute before slicing them in half. Serve hot and enjoy the melty goodness!