Lemon butter sauce to serve with steamed artichokes earlier this spring. Since then, I’ve started serving it with various things, including spaghetti, roasted vegetables, and couscous. It’s rich and buttery, with a vibrant, savory flavor thanks to the lemon juice and garlic. Lemon Butter Sauce is exactly what it sounds like: a butter-based sauce with broth or wine and seasonings (in this example, lemon, and shallots). There’s no need to thicken the sauce with flour because the butter emulsifies and acts as its thickener.