In a large saucepan heat chicken broth and bouillon cube over medium heat until hot.
In a Dutch oven, melt butter over medium heat. Add onions, carrots, celery, chives and garlic, and saute until tender. Season with salt and pepper. Add the flour and stir together until it becomes pasty and lump-free, about 2 minutes. Stir in the hot broth, heavy cream, sherry, chicken and frozen onions and peas. Bring to a boil then reduce to a simmer.
With a ladle, fill 6ovenproof ramekins or bowls with the filling. Place on baking sheet.
Sprinkle flour on countertop. Roll out dough an extra inch. Using a biscuit round or mold, cut out dough to cover the tops of your oven-proof bowls, with about 1/2-inch hangover, depending on their size. Crimp the dough over the edge of the ramekin. Brush with the egg wash and make 4 small slits on the top. Sprinkle with kosher salt and place on a baking sheet. Bake for 35 minutes. Remove from the oven and serve.