1In a bowl, add onion powder, garlic powder, dried oregano, dried parsley, kosher salt, black pepper, smoked paprika, olive oil, and lemon juice.
2Add the chicken thighs to the marinade and coat well. Cover with plastic wrap and set aside.
3Prepare the vegetables: slice six to eight Yukon gold potatoes, halve and deseed one delicata squash, and thinly slice one Spanish onion.
4In a bowl, combine the potatoes, squash, and onion. Drizzle with olive oil, and season with kosher salt and black pepper.
5Transfer the vegetables to a lined half sheet tray or cookie sheet. Place the marinated chicken thighs on a wire rack set on top of the vegetables. If you do not have a wire rack, you can place the chicken directly on top of the vegetables.
6Bake in a 400-degree oven for about 30 minutes, or until the internal temperature of the chicken thighs reaches 155 to 160 degrees Fahrenheit. The skin should be crispy.
7Let the chicken rest for about 10 minutes. Toss the vegetables back into the oven while the chicken rests.