Wash and dice the potatoes, then toss them into a baking dish along with the frozen green beans and sliced onion.
Drizzle with cooking oil and season liberally with salt and pepper. Mix well to coat everything.
Toss the 6 chicken legs in the garlic parmesan seasoning, reserving some if desired to add to the potatoes and vegetables.
Lay the seasoned chicken directly on top of the potatoes and vegetables.
Add a small amount of margarine to the top of each chicken leg.
Bake uncovered at 400 degrees for 50-55 minutes.
In the last 10-15 minutes, remove the chicken, toss the potatoes and vegetables, then add the chicken back on top, turning it over to brown both sides.
Return to the oven to finish baking.
