Add your chicken and seasoning to a mixing bowl. Move them around with a fork until they are fully coated. Cover, and set in the fridge while you prepare your vegetables.
Slice asparagus into 1 + ½ inch pieces, and slice onions into long thin strips. Next, add them to a mixing bowl with seasoning. Mix with a large spoon until they are fully coated.
Take a large piece of tinfoil and fold it in half, then bend the edges up about one inch to create a "lip." This will keep the chicken juice from getting on the vegetables. Place tinfoil on one side of the sheet pan, then add chicken.
On the other side of the pan add your veggies. Set the oven for 375 degrees, and bake for 30 minutes. If you want your veggies to have a little crisp, turn the oven to high broil for 2 minutes at the end.
Slice chicken, serve with vegetables and rice or a side of roasted potatoes! Enjoy!!