"Sofrito is the secret to many Hispanic Caribbean recipes. It is a fragrant aromatic puree of peppers, onions, garlic, herbs, and olive oil. The magic herb in this fragrant mixture is cilantro. My family's recipe produces a sofrito that is very flavorful, complex and oh-so-delicious! Use it in soups and stews as well as in rice dishes. Freeze whatever portions will not be used within 2 weeks. They will keep for about 3 months in the freezer."
Set oven rack about 6 inches from the heat source and preheat the oven's broiler. Line a baking sheet with aluminum foil.
Cut green bell pepper and red bell pepper in half from top to bottom; remove the stem, seeds, and ribs. Place peppers cut sides down onto the prepared baking sheet. Lightly brush with 2 teaspoons olive oil.
Roast under the preheated broiler until the skin of the peppers has blackened and blistered, 5 to 8 minutes. Transfer to a resealable plastic bag. Seal to let peppers steam as they cool, about 15 minutes. Remove skins under running water and discard. Chop flesh into large pieces.
Place pepper pieces, sweet chile peppers, onion, scallions, tomatoes, garlic, cilantro, culantro, olives, oregano, and capers in a blender or food processor. Blend, adding 1/2 cup olive oil and water in batches, until mixture is pureed but some chunks remain.
Divide blended mixture among four 16-ounce containers, filling each 3/4 of the way. Top each with 2 to 3 tablespoons olive oil to help preserve mixture. Close containers and refrigerate.