Heat oven to 400°F. In 10-inch ovenproof skillet, heat oil over medium-high heat. Cook onion in oil 3 to 4 minutes or until tender. Stir in beans, tomatoes, enchilada sauce, chicken, salt, cumin, chili powder, oregano and pepper. Heat to boiling. Reduce heat; simmer uncovered 15 minutes. In medium bowl, stir together Bisquick mix, egg and milk until smooth. Fold in 1/2 cup of the cheese and the cilantro; pour over simmering chicken mixture.