Storage & Make-Ahead
Refrigerate leftovers in an airtight container for up to 4 days. Reheat, covered, at 325°F (165°C) until warmed through, or microwave in short bursts.
To make ahead, assemble through the “Combine” step, cover, and refrigerate up to 24 hours. Top with the remaining cheese and bake just before serving.
This casserole can be frozen (tightly wrapped) for up to 2 months; thaw overnight in the refrigerator before baking.