Place potatoes in a shallow (microwave-safe) dish and add about 1/4-inch of water. Cover and microwave on HIGH for 3 to 4 minutes, until just soft. Drain and set aside.
Heat oil in a large skillet over medium heat. Add onion and saute 3 minutes, until soft. Add sweet potatoes, vinegar and paprika and cook 3 to 5 minutes, until potatoes are golden. Season, to taste, with salt and black pepper.