Sofrito is a staple in Puerto Rican cuisine, consisting of a saucy blend of herbs and vegetables used to season everything from rice dishes to soups. While many variations exist, culantro, a Mexican coriander and aji dulce -- or sweet peppers -- give traditional preparations of sofrito its characteristic flavor. Use whichever recipe for sofrito best suits your taste or access to ingredients; just make sure to roast the vegetables beforehand as the process intensifies their flavor.
Cut a red bell pepper, a yellow onion, a generous handful of aji dulces and any other vegetables your recipe calls for into large, evenly sized chunks. Many modern recipes also include tomatoes and green bell pepper. Roast your vegetables at 400 to 425 degrees Fahrenheit for 45 minutes to an hour, or until vegetable interiors are soft and creamy and the exteriors are crisp and caramelized. Traditionally, sofrito is ground with a mortar and pestle, but you can use a food processor instead. Let the roasted vegetables cool, then add to a food processor along with seasonings including culantro, cilantro and salt and pepper. You can also add a few dashes of ground coriander, a squirt of lemon juice or a few cloves of garlic, finely chopped or roasted. Process for about a minute, or until the sofrito reaches a saucy consistency.