While tater tots always find a way into my grocery cart, I all too often ignore the rest of the aisle. But frozen diced potatoes, often labeled hash browns or home fries, are one of the smartest shortcut ingredients to keep on hand. Often cooked as part of a classic diner-style breakfast, the potatoes, which are peeled and parboiled before they’re frozen, are just as great for cutting down on dinner prep.

The rest of the ingredients are likely already in your kitchen. Milk and sour cream form the tangy base of the sauce, which is thickened with a few tablespoons of flour. Dijon mustard, garlic powder, and diced onion are whisked in for flavor, followed by the frozen potatoes and handfuls of shredded cheese — anything from cheddar to Swiss to pepper Jack works great. Just before the casserole is done, finish with more cheese for a cap of gooey melted goodness.