Preheat oven to 350°F.
In a large bowl, combine the ground turkey, egg, quick cooking oats, tomato sauce, minced onion, and salt and pepper to taste. Once combined, form into 2-inch meatballs.
In a large frying pan, add vegetable oil over medium heat. Brown the meatballs for 1-2 minutes on each side. Tip- If you don't have a pan large enough to brown the meatballs, you can use two pans at the same time. Combine to one pan when simmering.
Add the cut celery stalks, cut carrot sticks, sliced stewed tomatoes (don't drain the can), and cream of chicken to the pan with the meatballs. Cover and simmer for 10 minutes over medium-low heat.
Add the drained cut green beans to the pan. Stir gently to combine. Dump the pan into a casserole dish. Put the quartered onion on the outside corners on top of the casserole dish. Cover the casserole dish with aluminum foil. Bake for 1 hour or until the carrots and celery are cooked and softened. Season with additional salt and pepper when serving. Enjoy!