Core and slice 6 medium apples (do not need to peel unless you prefer) in pan of salt water to prevent apples from turning dark. Drain and rinse.
Melt 3 Tbsp butter in a heavy skillet with a close fitting lid. Pour apples into melted butter. Add ½ cup sugar. Cover and cook very slowly until apples are tender, stirring only occasionally. Remove lid and cook down until thick syrup remains.