Cook potatoes in microwave on high until tender; cool. Place butter and onions in large bowl. Cook in microwave on high until tender, about 2 minutes. Stir in flour; add bouillon granules and water. Stir well; return to microwave and cook on high for 2 minutes until mixture is heated. Scoop out potatoes, leaving pieces in chunks. Add potatoes, evaporated milk, cheese, and seasonings to hot mixture. Return to microwave and cook on high 2-1/2 to 4 minutes until cheese is melted and soup is hot. Makes 6 servings.