This oven baked 3-ingredient oleo and onion potato casserole is the kind of simple side dish that proves pantry basics can still make something really comforting. It has that old-fashioned, summer-at-grandma’s-house feel, with tender sliced potatoes, sweet onion, and plenty of buttery richness baked together until everything turns golden and fork tender. It is especially handy on busy days when you want something warm and homemade without a long ingredient list.
Serve this casserole alongside grilled burgers, barbecue chicken, pork chops, meatloaf, or simple baked ham. It also works well with a crisp green salad, sliced tomatoes, or steamed green beans to balance the richness. If you are bringing it to a potluck, it pairs nicely with other classic comfort food dishes and stays satisfying even as it cools a bit.
Oven Baked 3-Ingredient Oleo and Onion Potato Casserole
Servings: 6
Ingredients
6 medium russet potatoes, peeled and thinly sliced
1 large yellow onion, thinly sliced
1 cup oleo, melted
Directions
1. Preheat the oven to 350°F and lightly grease a glass baking dish.
2. Layer half of the sliced potatoes in the baking dish, then top with half of the sliced onion. Drizzle some of the melted oleo over the layer. Repeat with the remaining potatoes, onion, and oleo.
3. Cover the dish tightly with foil and bake for 45 minutes.
4. Remove the foil and continue baking for 25 to 35 minutes, or until the potatoes are very tender and the top is lightly golden with browned onion edges.
5. Let the casserole rest for 10 minutes before serving so the layers settle and the buttery juices soak back into the potatoes.
Variations & Tips
Add seasoning: If you want a little more flavor while still keeping the recipe simple, add salt, black pepper, or a light sprinkle of garlic powder between the layers. Even a small amount can wake up the potatoes nicely.
Use a different onion: Sweet onions will make the casserole milder and a little sweeter, while white onions give it a sharper bite. Use whatever you already have on hand for an easy pantry-style version.
Slice evenly: Try to keep the potatoes sliced to a similar thickness so they cook at the same rate. If some slices are too thick, the casserole may brown on top before the center becomes fully tender.
Cover if browning too fast: If the top starts getting too dark before the potatoes are soft, loosely place the foil back on for the rest of the baking time. This is especially helpful if your baking dish is shallow.
Make it ahead: You can assemble the casserole a few hours in advance, cover it, and refrigerate it until ready to bake. This makes it easier to fit into a busy workday or get ahead before a family cookout.