Preheat oven to 500℉.
Drizzle 1 tbsp. olive oil on the bottom of a very large pan (I use a 12 x 15 metal pan with sides). Do not use glass or ceramic).
Place chicken, skin side up, on the pan without overlapping or overcrowding.
Place tomato wedges, onion pieces, and garlic around and in between chicken.
Squeeze lemon over chicken and vegetables.
Sprinkle with oregano, salt and pepper.
Bake 20 to 30 minutes, or until internal temperature of chicken reaches 165°F. Serve with pan drippings.