Ingredients
3 tablespoons salted butter, melted (plus a little extra for greasing the slow cooker)
2 pounds russet or Yukon Gold potatoes, thinly sliced (about 1/8-inch thick)
2 large yellow onions, thinly sliced (about 1/8–1/4-inch thick)
Sliced potatoes and onions ready for layering
Sliced potatoes and onions ready for layering
Directions
Lightly grease the inside of a 4- to 6-quart slow cooker with a bit of butter to keep the potatoes from sticking and to add extra flavor.
Peel the potatoes if you like (or scrub them well and leave the skins on for a more rustic bake). Slice the potatoes into thin rounds, about 1/8-inch thick, so they cook evenly and become tender all the way through.
Peel the onions, then slice them in half from root to tip. Lay each half flat and cut into thin slices, about 1/8–1/4-inch thick, so they soften and caramelize as they cook.
Buttering the inside of a slow cooker crock
Buttering the inside of a slow cooker crock
Drizzle 1 to 2 teaspoons of the melted butter into the bottom of the slow cooker and tilt the crock so it coats the surface.
Add a single, even layer of potato slices to the bottom of the slow cooker, overlapping them slightly like shingles. Sprinkle a loose handful of sliced onions over the potatoes, spreading them out so they cover the surface.
Drizzle a teaspoon or so of melted butter over this layer, letting it sink down between the slices. If you normally cook with salt and pepper, you may add a light pinch now, but the recipe is designed to be satisfying even without extra seasonings.
Repeat the layering process: potatoes, onions, and a light drizzle of melted butter, building up until all the potatoes and onions are used. Finish with a final drizzle of any remaining melted butter over the top so the upper layer turns glossy and golden as it cooks.
Layered potatoes and onions in the slow cooker
Layered potatoes and onions in the slow cooker
Cover the slow cooker with its lid and cook on LOW for 6 to 7 hours, or on HIGH for about 3 to 4 hours, until the potatoes are very tender when pierced with a fork and the onions are soft, translucent, and lightly caramelized around the edges.
Once cooked, let the potato and onion bake rest with the lid off for about 10 minutes. This allows the steam to settle and the buttery juices to thicken slightly, giving the potatoes a rich, glossy finish.
Finished potato and onion bake resting in the crock
Finished potato and onion bake resting in the crock
To serve, scoop down through all the layers so each portion has both potatoes and onions. Spoon any buttery juices from the bottom of the crock over the top of each serving for extra flavor and moisture.
Variations & Tips
This old-fashioned 3-ingredient bake is meant to be as plain and honest as the times it came from, but you can still make it your own while keeping the spirit of the dish. If you’d like a slightly different character without adding more true ingredients, play with the potato variety: Yukon Golds give a buttery, creamy texture, while russets turn softer and more rustic, almost like a loose casserole. Red potatoes will hold their shape more and give a firmer bite.
For deeper onion flavor, use one yellow onion and one sweet onion, or cook it a little longer on LOW so the onions caramelize further along the sides. If you have a very old slow cooker that runs hot, check the potatoes early so the bottom doesn’t overbrown; you can gently lift and stir the edges toward the center once during cooking if needed.
To stretch this meal for more people without adding ingredients, serve it over thick slices of toasted bread or alongside a big bowl of beans. Leftovers reheat well in a skillet with just a dab of butter: press them down a bit and let the bottom crisp for a few minutes to create buttery, golden potato cakes from yesterday’s supper.
Leftover potato bake crisping in a skillet
