Veggie swaps: Use green beans, broccoli, mushrooms, or zucchini—keep pieces similar in size for even cooking. Sauce thickness: The sauce thickens as it bakes; if you want it thicker, whisk 1 tablespoon flour into the cream before adding (or simmer a few minutes on the stove). Make ahead: Assemble in the baking dish up to 4 hours ahead; bake from cold and add about 5 minutes. Storage: Refrigerate leftovers up to 3 days; reheat covered at 350°F until warmed through.