Saute the onion, garlic and oil together to release the flavors.
Add chopped chicken and vegeta with onion mixture and saute together for 10 minutes. Stirring occasionally.
Add ¼ cup water if it appears dry.
Add mushrooms and continue cooking over medium heat for 5-10 minutes.
Pour mixture into a 9x9 baking pan.
Beat eggs in a separate bowl with sour cream and milk. Combine well.
Pour over the chicken mixture in pan.
Bake at 370F for 30 minutes.
When almost done, sprinkle finely chopped parsley and shredded cheese over top.