In a large Dutch oven or pot, heat butter over medium heat
Add onions, celery, mushrooms and carrots and sauté 3-5 minutes.
Add flour, and cook an additional 2 or 3 minutes.
Slowly add chicken stock, poultry seasoning, salt and pepper, stirring to incorporate flour. Bring to a boil, reduce heat to a simmer. Cover and continue cooking for about 15 minutes, or until vegetables are tender. Meanwhile, make dumpling dough.
Add Chicken and peas, bring to a gentle boil. Drop dumpling dough by spoonfuls onto gently simmering stew. Cover and cook for 15 minutes, without lifting lid.