Gazpacho with Serrano Chiles

Name: Gazpacho with Serrano Chiles
Ingredients: 4 large red bell peppers, about 1 1/2 lb. total; 1 1/4 lb. tomatoes; 1/2 English cucumber, peeled and cut into large chunks; 1/2 yellow bell pepper, seeded and cut into 1/4-inch dice; 2 serrano chiles, seeded and minced; 1 small red onion, finely chopped; 1 garlic clove, minced; 2 Tbs. extra-virgin olive oil, plus more for drizzling; 1 Tbs. sherry vinegar; 1 tsp. salt; 1 avocado, halved, pitted, peeled and cut into 1/4-inch cubes; 1 Tbs. snipped fresh chives; 1/2 tsp. dried oregano