Lemon slices help keep the fish moist during cooking. For a simple sauce, we combined lemon juice, white wine, and butter.
Place wine in a large, lidded skillet. Fold each sole fillet into thirds. Arrange in skillet; season with coarse salt and ground pepper. Lay two overlapping lemon slices on each piece of fish.
Bring wine to a boil; reduce heat to medium-low. Cover; simmer gently until fish is opaque throughout, 3 to 5 minutes. With a spatula, transfer fish to serving plates.
Return liquid in skillet to a boil; cook until reduced to 1/3 cup, 1 to 2 minutes. Add lemon juice; remove from heat. Whisk in butter until smooth. Season with salt; strain, if desired. Serve with fish; garnish with fresh herbs and pepper, if desired.