Heat oven to 425°.
Tossed potatoes, carrots, onions with 1 tablespoon of olive oil and ⅔ of the seasoning mix.
Spread vegetables on a large sheet pan in a mostly single layer.
Pat the chicken dry and rub it with the melted butter (or a little olive oil).
Sprinkle the remaining ⅓ of the seasoning mix evenly over both sides of the chicken, concentrating most of it on the skin side.
If you have 30–60 minutes before cooking, season the chicken and leave it uncovered in the refrigerator. The skin dries slightly and gets crispier.
Place chicken thighs on top, leaving about 1 inch between pieces.
Roast for 35 minutes.
Toss zucchini and green beans with 1 teaspoon of olive oil and salt and pepper.
Remove pan, stir potatoes and carrots, then add zucchini and green beans.
Roast another 15–20 minutes, until chicken reaches 185°, potatoes are fork-tender, and vegetables are browned.
Rest everything for five minutes before eating. Top with optional ingredients.
