You can cook slices of potatoes in a few pats of butter on top of the stove in a skillet or you can use a microwaveable dish and cook them in the microwave. They just won't be browned, but they will taste good.
Put a couple pats of butter in the bottom of the dish.
Slice your potatoes and layer them on top of the butter. Shake some salt and pepper on them. Add a little bit of chopped onion if you like.
Put them in the microwave for 4 minutes, check them for tenderness and turn them so they all get cooked. If they aren't fork tender, microwave them 2 more minutes and repeat until they are done. The more potatoes you are cooking, the longer it will take.