Instructions:
- Melt butter in a large Dutch oven or heavy-bottomed stockpot over medium heat. Add diced onion, carrots, and celery. Sauté gently until vegetables begin to soften (about 8-10 minutes). Do not brown.
- Sprinkle the 1/3 cup of flour over the softened vegetables. Stir constantly for 1-2 minutes to cook out the raw flour taste, creating a blonde roux.
- Slowly whisk in the chicken stock, adding it a cup at a time, ensuring no lumps form before adding more liquid.
- Add the thyme, rosemary, and bay leaf. Bring the mixture to a gentle simmer. Allow the soup to simmer uncovered for 15 minutes, stirring occasionally, until the liquid has thickened sufficiently.
- Remove and discard the bay leaf. Stir in the cooked chicken and frozen peas. Heat through for 2 minutes.
- Reduce heat to low. Stir in the heavy cream. Taste and adjust salt and pepper generously. Keep warm.
- If making biscuits: Preheat oven to 425°F (220°C). Whisk together the 2 cups of flour, baking powder, salt, and pepper for the topping. Cut in the cold butter until mixture resembles coarse crumbs.
- Stir in the buttermilk just until combined—do not overmix! Drop spoonfuls of dough onto a lined baking sheet and brush tops with the beaten egg wash.
- Bake the biscuits for 12-15 minutes, or until golden brown and cooked through.
- Ladle the hot Chicken Pot Pie Soup into deep bowls. Top immediately with 1-2 freshly baked drop biscuits and serve.