Step 1In a large saucepan, combine the sugar, water and lemon juice. Bring to a boil. Reduce to a simmer (med-low) and add lemon slices in a single layer.
Step 2Simmer over medium-low (uncovered) for 15 minutes, gently flipping once or twice during the cooking process.
Step 3Transfer the lemon slices to a wire cooling rack or waxed paper and let cool.