Heat grill for med-high heat. In bowl, combine 1 tsp chile powder, cumin, salt and pepper. Rub mix over both sides of each chicken. Oil grill grates. Grill chicken, covered, turning once for about 10 min, or until juices run clear. In small saucepan, heat oil over med-low heat. Add onions, cook, stirring often until tender. Stir in beans and remaining chile powder. Increase heat to med-high and simmer 2-3 min or until bubbly. Serve beans w/ chicken.