In a saucepan, cook the potatoes in boiling salted water until tender; drain. In a greased 2-1/2 qt baking dish, combine the potatoes, hot dogs, onion and peas. Combine soup, butter, mustard and pepper, gently stir into potato mixture. Bake, uncovered, at 350 for 25 minutes or until heated through. YIELD 6-8 servings. (*) Any cream soup will do busted by sooz