Meanwhile, in 12-inch nonstick skillet, melt 1 tablespoon of the butter over medium-high heat. Break egg into custard cup; carefully slide into skillet. Repeat with 3 more eggs. Immediately reduce heat to medium-low. Cook 4 minutes, spooning butter over eggs, until film forms over top and whites and yolks are firm, not runny. If desired, season to taste with salt and pepper. Repeat with remaining 1 tablespoon butter and 4 eggs.