Preheat oven to 375 F.
In a large pot, add olive oil, onions, celery and frozen mixed vegetables along with salt, black pepper and cayenne pepper.
Sauté for about 5 minutes on medium-high heat or until vegetables start to soften and sweat some of their moisture.
Sprinkle on the flour to the tops of vegetables and stir for about 1 minute.
Add chicken stock, Italian herbs, cream or milk and cooked chicken breast.
Cook until mixture starts to thicken.
Pour chicken mixture into a 9 x 13 baking dish.
To make the biscuits; in a large mixing bowl, add flour, baking powder and salt.
Stir together.
Add cold chunks of butter and work into the flour with fingers or pastry cutter until butter is in pea sized chunks.
Add cheddar cheese and toss in the flour with your hands or a spoon.
Add milk and stir together until a dough forms.
If you need, add a little more flour for the dough to pull together or more milk to form a dough ball that isn’t too dry or sticky.
Add dough in chunks on top of the chicken filling.
Bake for 25 minutes or until the tops are slightly golden and the biscuits are cooked through. You can stick a tooth pick into the center of the biscuit and if it comes out clean they are done.
Cool slightly before serving.