Easy Enchilada Soup

2 Cups Chicken Stock or Broth
1 cup picante style salsa
1 can (10 ounce) enchilada sauce
1 Tablespoon butter
1 teaspoon sugar
1 teaspoon salt
1 teaspoon ground pepper
2 cups cubed, cooked leftover rotisserie chicken
1 can (15 ounce) black beans
1 cup frozen  corn kernels
1 can (15 ounce) fire roasted tomatoes
juice of one lime
1 cup shredded Mexican cheese
1 avocado, peeled and diced
Optional garnishments: sour cream, cilantro, crumbled tortilla chips

In a large pot, add chicken stock, salsa, and enchilada sauce and bring to a boil over medium-low heat.  Stir in butter, sugar, salt and pepper.  Add chicken, beans, corn, tomatoes, lime and warm through,
Ladle soup into  bowls and sprinkle cheese and top with diced avocado.