Preheat the oven to 425°F. Line a large sheet pan with parchment paper or lightly grease it.

Pat the chicken thighs dry with paper towels and season both sides with the chive salt or seasoned salt.

Place the chicken thighs skin-side up on the sheet pan. Arrange the cauliflower, broccoli, and onion around the chicken, keeping everything in a single layer as much as possible.

Bake for about 30–35 minutes, or until the chicken is cooked through and the skin is browned and crisp. The thickest part of the chicken should reach at least 165°F.

Let the chicken rest for a few minutes before serving. Spoon parmesan sauce and any extra pan juices over the chicken and vegetables.