A good recipe for lemon sauce is one that calls for herbs, lemon zest, lemon juice, and either butter or olive oil. A good lemon sauce for desserts uses sugar, lemon zest, lemon juice, butter and cornstarch.
To make a savory lemon sauce to serve with chicken or vegetables, smash 1 clove of garlic with 1/4 teaspoon salt, crushing the garlic until a paste forms. Add the garlic and salt to a blender with 1/2 cup chopped fresh parsley, 1/3 cup chopped fresh mint, 1 1/2 teaspoons black pepper, and the juice and zest from 1 lemon. Blend everything together, gradually adding in 1/3 cup extra-virgin olive oil. Pour this sauce over cooked meat, or heat it to create a thicker sauce.
Another good savory recipe only requires 2 teaspoons grated lemon rind, 2 teaspoons fresh lemon juice and 1 teaspoon chopped fresh parsley mixed with 3 tablespoons melted butter.
To make a sweet lemon sauce that can be added to cakes and cookies, mix 1/2 cup granulated sugar, 1 tablespoon cornstarch and 1/4 teaspoon salt with 1 cup boiling water. Once the ingredients are dissolved in the water, stir in 1 tablespoon butter, 2 tablespoons fresh lemon juice and 1 tablespoon grated lemon peel. Serve this sauce warm.