Preheat the oven to 350 degrees F and coat 4 cups of a muffin pan with cooking spray. Fold each tortilla in half, then form into a cone, overlapping the sides. Fold up the point of the cone slightly, then press the tortilla into the prepared muffin pan to form a cup shape; coat with cooking spray. Transfer to the oven and bake until golden and crisp, about 15 minutes.
Meanwhile, combine the flour, cumin, chili powder, 1/2 teaspoon salt and a few grinds of pepper in a large bowl. Add the chicken and toss to coat.
Heat the olive oil in a large nonstick skillet over medium-high heat. Add the chicken in a single layer and cook, stirring occasionally, until lightly browned, about 2 minutes. Add the onion, celery, carrots and bell pepper and cook until the vegetables begin softening, about 2 minutes. Add the tomatoes and chicken broth to the skillet and bring to a simmer. Cook until the vegetables are tender and the sauce thickens slightly, about 5 minutes. Stir in the cilantro and season with salt and pepper.
Divide the chicken mixture among the tortilla cups. Top with the cheese.
Photograph by Andrew Purcell
Courtesy of Food Network Magazine