In microwavable 3- to 4-quart slow cooker insert or medium bowl, microwave potatoes on High 3 minutes 30 seconds to 4 minutes, stirring once, until thawed. Stir in beans. With back of spoon, press mixture in bottom and 2 to 3 inches up side of slow cooker; set aside.
In large bowl, beat eggs, half-and-half, salt and pepper with wire whisk until well blended. In 10-inch nonstick skillet, melt butter over medium heat. Add egg mixture; cook, stirring occasionally, until eggs are almost set.
Spoon half of egg mixture into slow cooker; top with half each of the soup, cheese and salsa. Layer with remaining egg mixture, soup, cheese and salsa.
Cover; cook on Low heat setting 3 to 4 hours.