Heat oven to 375. Grease 12 muffing cups.
In skillet, heat oil over med-high heat. Cook shicken in oil 5-7 minutes , stirring occasionally, until chicken is no longer pink in the center. Add onion and chicken broth; heat to simmering. Add frozen vegetables and seasonings. Heat until hot, stirring occasionally. Cool 5 minutes; stir in cheese.
In medium bowl, stir baking mixture ingredients until well blended. Spoon 1 scant T baking mixture into each cup. Top with about 1/4 c. chicken mixture. Spoon 1T. baking mixture onto chicken mixture in each cup.
Bake 25-30 minutes or until tests done. Cool 5 minutes, With thin knife loosed edges; remove from pan to rack, top side up. Cool 10 minutes longer and serve.