1. Saute onion and garlic in butter until softened.
2. Add spices and stir over low heat to mingle flavors.
3. Turn up heat and whisk in 2 3/4 C broth.
4. In a separate bowl, combine remaining 1/4 C broth and cornstarch to make a paste.
5. Bring broth in pot to a boil, then reduce heat and simmer; adding cornstarch mixture and stirring until broth thickens.
6. Add chicken, beans and yogurt and simmer gently until just heated through.
7. Serve with salsa, grated low-fat cheese and chopped cilantro.