Heat oil in a large deep skillet on medium-high heat. Add chicken, salt, pepper, onion powder, & garlic. Cook & stir 4 minutes until the chicken is no longer pink. Transfer to bowl.
Add broth gradually to flour in small bowl, whisking constantly until blended. Add to skillet; cook & stir on medium heat 2 minutes or until thickened. Add cream cheese & green onions. Cook & stir 3 minutes or until melted. Stir in chicken & frozen vegetables. Heat to a light simmer.
Stir baking mix, sour cream & milk just until baking mix is moistened. Spoon into 6 or 7 mounds over the mixture in the skillet. Cook on medium-high heat for 2 minutes. Cover skillet & cook on low for 15 minutes or until a toothpick inserted in dumplings comes out clean. Top with parmesan.