Sofrito is heavily emphasized as the third critical component in a "sofregit" base along with tomatoes and onions. Garlic is optional, as it is not considered an integral part of the standard "sofregit" recipe. Some "sofregit" recipes do not contain tomatoes at all, but are made more complex with the addition of diced vegetables such as leeks or bell peppers. In Italian cuisine, chopped onions, carrots and celery is battuto, and then, slowly cooked in olive oil, becomes "soffritto". It is used as the base for most pasta sauces, such as arrabbiata sauce, but occasionally it can be used as the
Bolognese sauce done to make it taste even smoother. Artusi recommended serving this sauce with a medium size pasta ("horse teeth") made from durum wheat. The pasta was to be made fresh, cooked until it was firm, and then flavored with the sauce and Parmigiano cheese. In the century-plus since Artusi recorded and subsequently published his recipe for "Maccheroni alla bolognese", what is now "ragù alla bolognese" has evolved with the cuisine of the region. Most notable is the preferred choice of pasta, which today is widely recognized as fresh tagliatelle. Another reflection of the evolution of the cuisine over the past