Take one-half of an old onion and chop it up fine. Take one small
carrot, wash it, scrape it, and cut it into transverse slices; do the
same with a stalk of celery, some parsley, and one fresh or canned
mushroom. Then take a slice of ham (raw if possible), fat and lean,
about four fingers wide and one finger high. Chop it up fine, and put
it into a medium-sized saucepan with one tablespoon of butter. When
the ham is colored, put in the chopped-up vegetables, one clove, salt,
and pepper, and stir constantly, allowing the vegetables to cook
thoroughly but not to burn, which will destroy the taste of the sauce.
It should be a golden color. A little red wine may be added if you
have it, but this is not necessary. Then add four fresh tomatoes, cut
into several pieces, the skins removed, and the seeds taken out. Allow
these to cook in the sauce until they sputter, then add a little water
(or bouillon if you have it), allow it to boil for a few moments more,
then take it off the fire and pass it through a sieve or fine
colander, pressing hard so that all will pass through. If it is too
thick after straining, add water or bouillon, and put it back and
allow it to boil again a few moments. This sauce can be used for
macaroni, gnocchi, left-over meat, egg, etc. The success of the sauce
depends upon the proper frying of the onion in it.
Source:
Simple Italian Cookery 
