Preheat your oven: Set the oven to 375°F (190°C). Grease a standard 12-cup muffin tin with nonstick spray or butter.

Prepare the filling:

• Heat the butter in a skillet over medium heat. Add the onion, garlic, carrot, and celery, and sauté for 4-5 minutes until softened.
• Stir in the chicken and peas. Sprinkle the flour over the mixture, stirring to coat everything evenly.
• Gradually pour in the chicken broth while stirring to prevent lumps. Let the mixture simmer for 2-3 minutes until it thickens slightly.
• Stir in the heavy cream, salt, pepper, and thyme. Cook for 2 more minutes. Remove the skillet from heat and let the filling cool slightly.

Assemble the pot pie muffins:

• Roll out the biscuit dough and cut each biscuit in half to make 12 pieces. Press each piece of dough into the muffin cups, pressing it up the sides to form a crust.
• Spoon 2-3 tablespoons of the cooled chicken mixture into each muffin cup, filling it almost to the top.

Seal the tops (optional): If you’d like a covered muffin, use extra dough to cut out small circles to place over the top of the filling. Press the edges to seal. Brush the tops with the beaten egg for a golden finish.

Bake: Place the muffin tin in the oven and bake for 15-18 minutes, or until the biscuit dough is golden brown and cooked through.

Cool and serve: Allow the mini pot pies to cool in the pan for 5 minutes before gently removing them. Serve warm, and enjoy!