Preheat the oven to 425°F (220°C) and grease a large casserole dish.

In a large bowl, combine chicken broth and half-and-half. In a skillet, melt butter and sauté onions, carrots, and celery for 5–7 minutes.

Stir in the flour and cook for an additional minute, then add the broth mixture and cook until thickened.

Mix in cooked chicken and peas, then pour the filling into the greased casserole dish.

In a bowl, combine Bisquick, buttermilk, cheddar cheese, and parsley to form a soft dough.

Drop biscuit dough over the filling, spacing it out to allow rising.

Bake for 22–25 minutes until biscuits are golden brown.