1. Preheat the oven to 400°F.

2. Add the olive oil to a heavy-bottomed pot or Dutch oven set over medium heat; swirl to coat the pan. When the oil is shimmering, add the carrots, celery, and onion and cook for about 4 minutes, or until soft and aromatic. Add the garlic and frozen peas. Cook for about 2 more minutes.

3. Add the gravy, ham, and turkey to the pot and mix to combine with the vegetables. Season with salt and pepper if needed. Pour the mixture into pie crust.

4. Finally, spread or pipe the mashed potatoes over the top of the pie filling and sprinkle the top with the shredded cheddar.

5. Place on the middle rack in the preheated oven and bake for about 30 minutes, or until the mashed potatoes are golden on top and the crust is baked. Top with chives if desired. Let cool just slightly before serving.

Optional: A second gluten-free prepared pie crust may be used to top the pot pie in place of mashed potatoes. Follow package instructions.