Line crock pot with foil, leaving enough to cover the potatoes when finished – this will help to not stick and to steam the potatoes – also to keep them from getting discolored or mushy. Layer half each of the bacon, onions and potatoes in the crock pot. Season to taste with salt and pepper and dot with (real) butter. Repeat layers of bacon, onions, potatoes and cheese. Dot with butter. Cover with remaining foil. Cover and cook on low for up to 6 hours (check at 4 hours – depending on your crock pot). Add cheese for the last 20 – 30 minutes and enjoy