3 tablespoons butter
3 tablespoons all-purpose flour
2 cups chicken stock
1 (4 ounce) can Old El Paso chopped green chiles
½ teaspoon ground cumin
1 cup plain Greek yogurt or sour cream
24 Old El Paso soft flour tortillas, halved
2 cups shredded cooked chicken
2 (14-ounce) cans White Northern beans, rinsed and drained
3 cups shredded Pepper Jack cheese
1 avocado, peeled, pitted and diced
¼ cup chopped fresh cilantro leaves