There are mainly three kindsof soffritto:
With garlic
With onion
With onion, carrots and celery
Depending on the sauce we are making we start with either one or the other.
Examples:
Basic sauce tomato and basil: need oil and garlic, like the simple but delicious ‘aglio olio e peperoncino ‘ pasta and fish or sea food ones.
Matriciana pasta with pancetta? Oil and onion
Sauce with meat? Always onion, carrots and celery
When I say sauce with meat, I refer to:
Sauce with sausage, pork spare ribs, pork meat, meat balls, ragù etc.
The sauce you use with pasta, lasagna, polenta.