Add the chicken, Everything But the Leftovers seasoning, bone broth, and fresh savory to a crockpot. Cook on low until done - about 2 hours for smaller pieces, but adjust as needed.
In a cast iron or oven-safe skillet, melt the butter over medium heat. Add onion and celery, cooking until softened.
Then stir in the frozen vegetables and seasonings; cook for 5 minutes.
Sprinkle flour over the veggie mixture and stir until everything is well coated. Add in the cooked, chopped chicken and its broth. Bring to a gentle boil and simmer until the sauce thickens.
Once thickened, lay the puff pastry (or biscuits) over the top of the filling. Brush the pastry with beaten egg for a golden finish.
Transfer the skillet to the oven and bake at 400°F for 20-25 minutes, or until the pastry is puffed and golden brown.