Bone-in, skin-on chicken thighs roast over onions and fresh tomato. A rub of tomato paste, garlic, lemon, and warm spices adds bold flavor without marinating, and a brief broil gives the tops color.
Get ready. Set one oven rack in the center and another about 6 inches from the broiler. Preheat the oven to 425°F.
Season the chicken. Sprinkle the thighs with kosher salt on both sides and underneath the skins. Set aside briefly while you make the rub.
Make the spiced tomato rub. In a small bowl or measuring cup, whisk together the tomato paste, olive oil, lemon juice, garlic, oregano, smoked paprika, cumin, and black pepper.
Coat the chicken. Spread the rub over both sides of the thighs and underneath the skins.
Fill the baking dish. Brush the bottom of a 9-by-13-inch baking dish with a splash of olive oil. Spread about three-quarters of the sliced onions across the bottom and arrange the chicken on top. Tuck the remaining onions and sliced tomato between the thighs. Pour the water into the corners of the dish without washing the rub off the chicken
Bake. Bake on the center rack for about 40 minutes, until an instant-read thermometer inserted into the thickest part of a thigh, away from the bone, reads 165°F.
Broil. Move the dish to the upper rack and turn the broiler to high. Broil for 1 to 3 minutes, watching closely, until the tops brown lightly.
Rest and serve. Remove the dish from the oven and let the chicken rest for 5 to 10 minutes. Sprinkle with parsley and serve with the onions, tomato, and pan juices.
To use chicken breasts: Substitute bone-in, skin-on chicken breasts. Bake at 375°F for 30 to 35 minutes, until the thickest part reaches 165°F. If the skins need more color, broil briefly and watch closely.
Storage: Refrigerate leftover chicken, vegetables, and sauce in an airtight container for up to 4 days.
To reheat: Put the leftovers in a covered baking dish at 325°F. Add a little water or broth if needed and reheat until the chicken reaches 165°F.