Pre-heat oven to 425 deg
In a pot, add around 1-2 tablespoon of oil and cook your onion, celery, and garlic on medium heat for a few minutes until softened.
Add in ½ stick butter and 2 tablespoon flour and stir for around 1-2 minutes with the veggies
Add in around 3 cups of chicken broth
Add in 1 cup of heavy cream
Add in 1 tablespoon of chicken bouillon
Add in the frozen peas and carrots
Add your chicken into the mixture
Let your mixture simmer on medium low for around 7-10 minutes or so to thicken. If the mixture gets too thick, add more chicken broth. If the mixture is too soupy, continue to let it reduce for another 5 minutes.
While your pot pie mixture simmers, make your cheddar bay biscuit mixture using the directions on the box.
Add your pot pie mixture to large cast iron or baking dish
Top with your cheddar bay biscuit mix and spread evently
Bake at 425 for 15-20 minutes
Brush with melted garlic butter on top (the packet comes with cheddar bay biscuit mix)