‘Christmas fan favorite’—Just 3 ingredients. I make it all season because it’s too easy not to.

If you have a few extra minutes and ingredients on hand, this casserole is super easy to dress up. For a cheesier version, stir in 1–2 cups of shredded cheddar or Colby Jack before baking, and sprinkle a little extra on top for a golden, bubbly finish. Want more texture? Add a crunchy topping by sprinkling crushed butter crackers, cornflakes, or seasoned breadcrumbs over the casserole during the last 10–15 minutes of baking. You can also mix in cooked, crumbled bacon or diced ham to make it more of a main dish—this is a great trick for using up holiday leftovers. For a lighter feel, swap half of the sour cream for plain Greek yogurt; it keeps things creamy but adds a bit of tang and protein. If you’re prepping ahead, assemble the casserole the night before, cover tightly, and refrigerate; just add an extra 5–10 minutes to the bake time if it goes into the oven cold. And if you’re cooking for a smaller household, divide the mixture between two smaller baking dishes, bake one now, and freeze the other (unbaked, tightly wrapped) for a future busy weeknight or last-minute potluck invite.