Ingredients
Method
- Preheat your oven to 375°F and grease a 9x13-inch baking dish with cooking spray.
- Heat olive oil in a large skillet over medium-high heat. Add ground beef and diced onion, breaking up the meat with a wooden spoon. Cook until the beef is completely browned and onions are translucent, about 6-8 minutes. Season with salt and pepper, then drain excess fat.
- In a medium bowl, whisk together cream of mushroom soup, milk, and onion soup mix until smooth.
- Arrange half the sliced potatoes in your prepared baking dish, overlapping slightly. Spread the cooked ground beef mixture evenly over the potatoes. Pour half the soup mixture over the beef, then add remaining potatoes in another overlapping layer. Top with remaining soup mixture, ensuring it reaches the edges.
- Cover tightly with aluminum foil and bake for 35 minutes. Remove foil, sprinkle cheddar cheese evenly over the top, and bake uncovered for another 10-15 minutes until cheese is bubbly and potatoes are fork-tender.
Notes
Slice potatoes the night before and store in water in refrigerator for time-saving. Don't slice potatoes too thick or they won't cook properly. Always drain ground beef fat to prevent greasiness. Let casserole rest 5 minutes after baking to help layers set. Can be assembled up to 24 hours ahead and refrigerated. Store leftovers in refrigerator for up to 4 days or freeze for up to 3 months.
