There's nothing quite like a creamy lemon sauce for pasta dishes! But if you've ever had a sauce separate on you, you know how nerve-racking it can be to add lemon juice to a sauce you've already worked so hard on. For best results, wait to add lemon juice until after a cream sauce has already thickened. Also, make sure you're using heavy cream (as opposed to milk, which has less fat and is more prone to separating when acid is added). If you're worried about curdling, you can also add the lemon juice in stages. (For example, add a bit of lemon to the softened garlic; let it reduce a bit before adding the cream. Add another splash of lemon once cream has thickened; add remaining juice when you mix the sauce into the pasta.)