Sofrito is a general term for a Latin cooking base. It is used in Italian and Spanish cuisines, and across Latin America and the Caribbean and beyond to add delicious flavor to soups, meat, braises, and more. It is a puree of peppers, onions, garlic, and herbs. In nearly any recipe where you might start by chopping these ingredients and sauteing them, you can just throw in a few sofrito cubes and start cooking! Unlike Italian and some Spanish sofritos, the Puerto Rican recaito (named so because of the use of the plant "Recao" (also called Spiny Cilantro, or Culantro), doesn't contain tomatoes.
Wash and chop all ingredients into rough chunks. No need to remove the cilantro stems, as they are tender and flavorful.
Using a food processor (a blender is not recommended), process sofrito, in batches if necessary, until finely incorporated, but not liquified.
Using dedicated ice cube trays (don't use the trays for ice cubes after using for sofrito or your drink will taste BAD!), freeze sofrito in cubes, then, if desired, transfer to freezer bags for long term storage. Each cube is about a tablespoon, but measuring is not super important. Flavor is good, give or take a little! Fresh sofrito lasts about a week in the fridge. Just pop a cube or two or 3 into your saute pan to start your cooking, or thaw and stuff under chicken skin before roasting. The possibilities are endless!
I have two other Puerto Rican recipes that feature sofrito- Sopa de Salchichon ("salami soup") and the official dish of Puerto Rico, Arroz con Gandules ("Rice with pigeon peas").