- In a large non-stick skillet over high heat, brown the onions in the oil. Add the thyme. Season with salt and pepper. Set aside.
- Line the bottom of the slow cooker with a third of the potato slices. Season with salt and pepper. Cover with half of the onions. Continue with a third of the potatoes and the remaining onions. Drizzle with the broth and finish with the remaining potatoes. Press lightly. Season with salt and pepper. Brush with the melted butter.
- Cover and cook on Low for 6 hours. It can be maintained on Warm for up to 4 hours.