Heat a 12" Dutch oven using 20-22 briquettes bottom until hot. To hot oven add bacon grease, chicken and garlic; season with salt and black pepper to taste. Cook chicken stirring frequently until chicken is no longer pink. Add onions and potatoes and continue cooking until onions are translucent but still firm. Stir in mixed vegetables, soup, evaporated milk, poultry seasoning and Worcestershire; season with salt and pepper. Let mixture come to a low boil. Unroll the crescent rolls and create a top crust by layering flat rolls across the top of ingredients. Reduce the heat on bottom to 8-10 briquettes and add 14-16 briquettes to the lid. Bake for 25-30 minutes until the rolls are golden brown and flaky. Check to make sure potatoes are cooked through. If not, then remove all briquettes from the lid and continue to cook maintaining bottom heat to keep pie bubbling an additional 15 minutes until potatoes are cooked through.