Heat oven to 400 degrees.

Line a rimmed baking sheet with tin foil.

Spray foil with olive oil baking spray.

Put the chicken thighs into a large bowl. Add 2 tablespoons of olive oil, 1 teaspoon Italian seasoning, 1 teaspoon garlic powder, 1/2 teaspoon steak seasoning, 1/2 teaspoon chicken seasoning, 1 tablespoon lemon juice, and1 tablespoon Dijon mustard. If desired add sliced garlic cloves.

Stir the chicken so that every piece is coated evenly, then cover with plastic wrap and marinate in the fridge for at least an hour.

Place marinated chicken thighs skin-side up on the rimmed sheet pan.

In the bowl that had contained the chicken add trimmed brussels sprouts (if small, leave whole, if large, cut in half, red onion, potatoes, and garlic clove. Add 1 tablespoon olive oil, 1 teaspoon Italian seasoning, 1 teaspoon garlic powder, 1/2 teaspoon steak seasoning, 1/2 teaspoon chicken seasoning, 1 tablespoon lemon juice, and 1 tablespoon Dijon mustard. Stir so that vegetables are well coated.

Place vegetables around chicken pieces on the sheet pan.

Bake uncovered at 400 degrees Fahrenheit for 30-35 minutes or until the juices run clear. If you have a meat thermometer, check to see that the internal temperature of a chicken thigh has reached 165 degrees Fahrenheit. Then crisp the skin up and brown it under the broiler for a few minutes. Watch carefully as it is quick to burn.