Place the salmon skin down on a baking sheet lined with foil. Top the salmon with pieces of butter and sprinkle generously with the garlic salt. Finally, top the salmon with lemon slices.
Bake the salmon at 425°F for 6-8 minutes, depending on the thickness of the salmon fillet, until the salmon is almost cooked. Then, turn the oven up to high broil and cook for 3-4 more minutes.