Preheat your oven to 375 °F (190 °C) (inferred).
In a bowl, whisk together olive oil, tomato paste, minced garlic, lemon juice, smoked paprika, onion powder, oregano, salt, and black pepper.
Pat chicken thighs dry. Add the thighs to the marinade and toss so they’re coated well.
In a roasting tray, spread the quartered potatoes, bell pepper and onion in a single layer on the bottom.
Place the chicken thighs skin side down on top of the vegetables.
Roast in the oven for 40 minutes, flipping the chicken halfway (so skin side ends up on top) to get that golden crisp. Broil for 5 minutes at the very end. Make sure not to burn it.
After roasting, allow the chicken to rest for 5 minutes. Garnish with chopped parsley and serve.