In skillet over medium heat, add butter, onions, celery and carrots.
Sprinkle generously with salt and pepper.
Sauté 5-10 minutes or until veggies are becoming transluscent and tender.
Add corn, peas, parsley, sage and thyme.
Sauté an additional 5 minutes so the corn and peas are saturated with all the spices.
Spray a 9x13” glass baking dish with cooking spray.
Spread veggie mixture over the bottom of the dish.
Sprinkle chicken over top of the veggie mixture. Do not stir.
Mix flour, baking powder and salt in a small mixing bowl and stir to combine.
Add milk and whisk until no lumps remain. (If using half-and-half, increase amount to 2 cups).
Spread milk mixture over top of the chicken but do not stir.
Combine condensed chicken soup with 2 cups chicken broth or stock in a medium mixing bowl and whisk until thoroughly combined.
Pour chicken soup mixture over top of milk mixture.
Do not stir.
Bake at 350° for about an hour to an hour and ten minutes.