Chicken Pot Pie Casserole

Place chicken and broth in a pot and bring to a simmer over medium heat. Simmer about 10-12 minutes, until cooked through. While chicken is cooking, begin to prepare the topping. Move chicken to medium bowl, and pour broth through a sieve into a separate bowl and reserve. Return pot to stovetop. Preheat the oven to 400 degrees. In a large bowl, combine flour, baking powder, salt, pepper, and cayenne. Add in butter pieces and use pastry cutter, or your fingers, to rub butter into flour mixture until it becomes course crumbs. Mix in parmesan cheese. Add cream and stir until just combined. Crumble mixture into large, pieces onto a baking sheet lined with parchment. Bake topping until it starts to brown, about 15 minutes, turning pieces halfway through. In the pot, heat olive oil over medium heat. Add onion, carrots, potatoes, salt, and pepper. Cover and cook, stirring occasionally, until veggies are tender, about 10 minutes. While veggies are cooking, cut the chicken into bite-sized pieces. When the veggies are done, move them into the bowl with the chicken. In the same pot, melt butter over medium heat. Stir in flour and mix until combined. Slowly whisk in chicken broth and milk. Bring to a simmer and stir until sauce thickens, about 5 minutes. Add salt and pepper and remove from heat. Stir the chicken, veggies, and frozen peas into the sauce. Pour the mixture into a greased 9x13 pan. Break topping into smaller pieces and scatter on top. Bake at 400 degrees until the top is browned, about 15 minutes. Let sit for 10 minutes, then enjoy!