Heat 2 tablespoons olive oil in a large skillet. Add 1/3 of the chicken thighs in a single layer; cook until browned, about 3 minutes per side. Transfer to a large pot. Repeat with remaining olive oil and chicken thighs.
Pour stewed tomatoes, diced tomatoes, corn, potatoes, onions, mushrooms, green bell pepper, green onions, Worcestershire sauce, and pepper into the pot. Cover and cook over very low heat until potatoes are tender and flavors combine, about 4 hours. Season with black pepper.