INSTRUCTIONS Place the chiles in a food processor with the stock, onions, garlic, cumin, oregano, coriander, salt, and pepper; purée.In a saucepot over medium heat, melt butter and whisk in flour. Add milk and yogurt, and raise the heat a bit. Add the chile puree and simmer to thicken the sauce, 15 to 20 minutes.Preheat oven to 350 degrees F.While the sauce is cooking, place a large skillet over medium-high heat and add the olive oil. Season chicken breasts with salt and pepper and brown 3 to 4 minutes on each side then remove from the heat.Add the rice, 2 cups hot water, and 2 cups of the poblano sauce to a casserole dish and stir to combine well. Lay the chicken breasts on top of the rice and spoon the remaining sauce over the chicken. Cover tightly with foil and bake for 30 minutes.Remove the foil, top with cheese, and bake 10 more minutes, or until the chicken reaches an internal temperature of 165 degrees.