The recipe for my private tomato sauce.

four or five medium-sized onions (white, not red)
the green part of a package of scallions
one 200-gram package of sliced bacon or ham
optional: lettuce or cabbage leaves (white, not red)
one 800-gram can of peeled crushed tomatoes
a similar amount of concentrated tomato paste
one 750-gram plastic bottle of ketchup
one 250-milliliter carton of creme fraiche
butter, olive oil. soy sauce, pepper, sweet paprika, zaatar

Oil a large deep skillet or wok with equal amounts of butter and olive oil.
Mince very small: the onions, scallions, bacon or ham, and lettuce or cabbage.
Place in the skillet or wok and wet down with soy sauce.
Fry until all the ingredients have become equally soft.
Remove from the stove top.
Add: the tomatoes, tomato paste, ketchup, and creme fraiche.
Add one teaspoon each of white pepper, sweet paprika, and zaatar.
Mix thoroughly and return to the stove top.
Simmer on low heat for 15-30 minutes. During this time the sauce is in constant danger  
          of burning, so you must mix it constantly, and never turn your back on it.
When passing the spatula across the bottom of the skillet or wok produces a loud sizzling noise, 
          remove from the stove top.
Liquify with a hand-held blender to produce an even consistency of semi-liquid paste without solid 

The sauce is now ready to use -- or it can be divided into separate portions that will keep in the freezer for months.