Preheat oven to 500° F. Spray a large baking sheet with cooking spray or line with parchment paper or foil.
Chop all the veggies into large pieces. On a separate plate or cutting board chop all the chicken in large cubes. Place the chicken and veggies on the prepared baking sheet. Add garlic, olive oil, and Ranch seasoning. Toss to combine.
Bake for 15 to 20 minutes or until the veggies are charred and chicken is cooked through. Serve immediately and enjoy with rice, tortilla or as is!