Stewed Chicken and Buttermilk Biscuit Pie

Ingredients

• 5 pounds chicken, washed and trussed
• 1 carrot, peeled and coarsely chopped
• 1 yellow onion, peeled and coarsely chopped
• 1 stalk celery, cut into 1" pieces
• 1 leek, washed and cut into 1" pieces
• 6 parsley sprigs
• Pinch of dry thyme
• 1 bay leaf
• 5 cups chicken stock
• 1 cup sugar snap peas or English peas
• 1 carrot, peeled and diced
• 1/2 pound fresh mushrooms, diced
• 3 tablespoons unsalted butter
• 4 tablespoons all purpose flour
• 2 1/2 cups (300 g) flour
• Salt and freshly ground pepper
• 1 tablespoon baking powder
• 1/2 cup unsalted butter, room temperature
• 1 cup buttermilk, room temperature