If using a baking dish - melt the butter in a saute pan, add the onion to the butter. Saute until onion is softened, add the garlic, stir and cook 1 more minute. Add the potatoes to the saute pan, toss to coat. Place the potatoes into a baking dish, place the baking dish into the oven, bake at 375 degrees for 45 minutes ( turning potatoes once with a spatula halfway through baking) or until golden brown and soft. Season with salt and pepper, sprinkle with chopped parsley.