In large boiler or stock pot, sauté onion in butter for 3-4 minutes. Add ham, cook 5-8 minutes. Add about 1/2 cup water. Add potatoes and mixed vegetables. When ham, potatoes and mixed vegetables are tender, add soup, milk and sour cream. Heat thoroughly. If mixture seems to thin add 3-4 tbsp. Instant potatoes or remove about 1 cup mixture, place in blender and puree it. Return to pot. If mixture is too thick, add more milk. Garnish with green onions, cheddar cheese or bacon crumbled. Serve with toasted garlic bread.