Gazpacho with Serrano Chilies

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 chilies, 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