Preheat the oven to 375°F. Spray a 9x13 baking dish with cooking spray, set aside.

In a large skillet over medium heat add the butter and let it melt.

Add the onions, stirring occasionally until soft and translucent, 5-8 minutes.

Add the garlic, stirring constantly until fragrant, 30 seconds.

Add the frozen veggies to the pan and cook until heated through, stirring occasionally about 10 minutes.

Add the half and half and cream of chicken soup, whisk it in until combined.

Add the turkey and pepper, stir it in until coated in the sauce. Heat until it just starts to bubble, taste, and add salt or more pepper if needed, then pour the mixture into the prepared baking dish.

In a large bowl, stir together the flour, baking powder, sugar, salt, and baking soda. Add the butter to the bowl and cut it in with a pastry cutter, two forks, or you can use your fingers. The mixture should resemble coarse sand with bits of butter no larger than peas throughout.

Add ¾ cup of the buttermilk and stir it in until combined, there may be some loose flour leftover in the bottom, that’s okay.

Turn the mixture out onto a floured work surface, knead it a few times until it comes together to form a dough. Roll out the dough into a rectangle ½ inch thick. Cut into 8 even pieces. 

Place the biscuits right on top of the pot pie filling.

Brush the tops with the remaining buttermilk.

Bake for 20-25 minutes until bubbly and the biscuits are lightly golden brown.

If the biscuits aren’t browned enough, put the broiler on high until your desired browning.