Process bell pepper, ajies dulces, and garlic in large (14-cup) food processor until mixture is smooth, about 1 minute, scraping down sides of bowl as needed. Add onion and process until smooth, about 30 seconds. Add cilantro and cilantro and process until herbs are finely minced, about 30 seconds. (Sofrito can be refrigerated for up to 1 week or frozen for up to 3 months.)