Ingredients
1 1/2 pounds russet potatoes, peeled and thinly sliced (about 1/8-inch thick)
1 pound ground beef (80–90% lean)
2 (10.5-ounce) cans condensed cream of mushroom soup
1 1/2 cups whole milk (or 2% milk)
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish or a deep vintage-style ceramic casserole dish with a little butter or cooking spray so the potatoes don’t stick.
In a large skillet over medium heat, crumble in the ground beef and cook, stirring and breaking it up with a spoon, until it is just browned and no longer pink, about 6–8 minutes. Drain off any excess grease so the casserole doesn’t turn out greasy. Season lightly with salt and pepper if you like, but remember the soup has salt too.
In a medium mixing bowl, whisk together the condensed cream of mushroom soup and the milk until smooth and pourable. This will be your creamy white sauce that bubbles up around the potatoes and beef as it bakes.
Lay half of the sliced potatoes in an even layer on the bottom of the prepared baking dish, overlapping the slices slightly like shingles so there are no big gaps. Try to keep the layer fairly even so everything cooks at the same rate.
Sprinkle half of the browned ground beef evenly over the potatoes, making sure to reach the corners so every scoop gets some meat.
Pour about half of the soup-and-milk mixture slowly over the potatoes and beef, letting it seep down into the layers. Gently tilt the dish if needed so the sauce spreads out a bit.
Repeat the layers with the remaining potatoes, then the rest of the ground beef, and finally the remaining soup mixture poured evenly over the top. Use the back of a spoon to nudge any dry potato edges down into the sauce so they don’t dry out.
Cover the baking dish tightly with foil to help the potatoes steam and get tender. Place the dish on the center rack of the preheated oven and bake for 50–60 minutes, until the potatoes are mostly tender when pierced with a fork.
Carefully remove the foil (watch for steam), then return the uncovered casserole to the oven and bake for another 20–25 minutes, or until the top is bubbly, lightly browned around the edges, and the potatoes are completely tender. The sauce should be thickened and creamy, not runny.
Let the casserole rest on the counter for about 10–15 minutes before serving. This short rest helps the layers settle so you can scoop out neat, hearty portions with a big spoon. Serve warm, straight from the dish, and don’t be surprised if everyone goes back to scrape the last bits of creamy sauce from the corners.
Variations & Tips
For picky eaters, you can swap the cream of mushroom soup for cream of chicken or cream of celery if they’re not fans of mushrooms, while still keeping the same four-ingredient structure (potatoes, beef, condensed soup, and milk). If you’d like a slightly richer casserole, use half-and-half instead of milk, or stir a small splash of milk into the leftovers before reheating to bring the creaminess back. You can also adjust the texture by slicing the potatoes very thin with a mandoline so they get extra soft and almost melt into the sauce, which kids tend to love. For a bit more flavor without adding extra ingredients, brown the beef well until you get some caramelized bits on the bottom of the pan, then scrape those into the casserole—that deep, browned flavor makes it taste like it cooked all day. If your family likes a little color, sprinkle chopped fresh parsley over the top after baking, or serve with ketchup on the side for the kids who want to dip each bite. To make ahead on a busy winter day, assemble the casserole in the morning, cover tightly, and refrigerate; when you’re ready to bake, let it sit on the counter while the oven preheats and add an extra 10–15 minutes to the baking time if it’s going in cold.