Step 2
Melt butter in a large skillet over medium-high heat. Cook tilapia in melted butter until golden brown on both sides, 2 to 3 minutes per side. Reduce heat to medium, and season fillets with salt if desired. Sprinkle the tilapia with the remaining Parmesan cheese, cover, and continue cooking until the Parmesan cheese has melted, about 5 minutes.