Layer
Drizzle 1–2 tsp melted butter into the bottom. Add a layer of potatoes, then onions, then a drizzle of butter. Repeat until all ingredients are used. Finish with a final drizzle of butter on top.
Cook
Cover and cook on LOW for 6–7 hours or HIGH for 3–4 hours, until potatoes are fork‑tender and onions are soft and lightly caramelized.
Rest
Remove lid and let sit 10 minutes. This allows steam to settle and buttery juices to thicken.
Serve
Scoop down through all layers so each portion has both potatoes and onions. Spoon buttery juices from the bottom over each serving.
