Chicken Enchilada Soup

2 tablespoons butter, margarine or olive oil
4 boneless, skinless chicken breast halves, diced
2 teaspoons minced garlic
1(4 ounce) can diced green chiles
2 (14 ounce) cans low sodium chicken broth
8 ounces reduced fat sour cream
1 (10 3/4 ounce) can chili cheese dip*
8 ounces frozen chopped spinach, defrosted and drained well
4 ounces reduced fat shredded Cheddar or Monterey jack
    cheese, for garnish, optional

Heat the butter, margarine or olive oil in a Dutch oven. Add the chicken and saut