Cook the chicken:Add 1 to 1½ lbs boneless, skinless chicken breasts to a slow cooker. Cook on high for 3 hours or low for 6 hours, then shred or dice. (Shortcut: Use rotisserie chicken if you’re short on time.)
Preheat the oven to 400°F.
Sauté the veggies:In a cast-iron or oven-safe skillet, melt 2 tablespoons butter over medium heat. Add diced onion, garlic, and low-carb mixed veggies. Season with salt and pepper. Cook for about 5 minutes, or until the onions are soft and translucent.
Make the creamy filling:Stir in the heavy cream, chicken broth, poultry seasoning, thyme, and rosemary. Sprinkle xanthan gum on top and stir to combine.
Simmer:Cover and simmer the filling for 5 minutes until it begins to thicken. Note: Keep it covered to prevent evaporation—you want a creamy texture, not a dry filling.
Add chicken:Stir the cooked chicken into the sauce and remove the skillet from heat.
Make the biscuit topping:In a bowl, whisk together melted (and slightly cooled) butter, eggs, sour cream, and a pinch of salt. Add coconut flour and baking powder; stir until combined. Fold in shredded mozzarella and cheddar cheese.
Assemble the pot pie:Drop the biscuit batter by spoonfuls over the filling—do not spread it out. The batter will puff and brown as it bakes.
Bake:Transfer skillet to the oven and bake for 15–20 minutes, until the biscuit topping is cooked through and golden.
Optional broil:For extra color, switch the oven to broil for 1–2 minutes. Keep a close eye so it doesn’t burn!
Garnish & serve:Remove from oven, sprinkle with dried parsley if desired, and let rest for 5 minutes before serving.