Sprinkle chicken with thyme, salt and pepper; set aside

In 12 inch skillet, heat butter and oil over medium heat. Cook garlic in butter mixture 1 to 2 minutes, stirring frequently. Add chicken. Cook uncovered 8 to 12 minutes, turning once, until light brown.

Stir in frozen vegetables. Cover; cook 6 to 8 minutes, stirring occasionally, until vegetables are hot and crisp-tender and juice of chicken is clear when center of thickest part is cut (at least 165°).