Spaghetti with Italian Tomato Sauce

Every person in Italy probably has his recipe for the tomato sauce used to dress pasta: some people still remember what they learned from their mother when they were children; other use those promoted by some more or less famous chef; others tell tall stories about the famous and most secret one handed down by  grandmother Gertrude at her time of dying.
Mine is simply a refinement of the sauce that I had to learn to prepare when I started living alone because I had to eat something. Over the time it has been varied due to numerous additions from experience and suggestions from friends, for example I use thyme since I tasted it for the first time in the sauce prepared by a friend's wife in place of the more common oregano.
In short it is a unpretentious recipe and quite easy to prepare, the addition of cherry tomatoes at the end is optional and recommended only if you can find some fresh and tasty.

Ingredients for two servings

½lb. spaghetti
1¾ lbs. tomatoes (preferably San Marzano kind)
½lb. cherry tomatoes
1 onion
2 basil leaves
1 sprig of thyme
3 cloves of garlic
olive oil
salt
grated pecorine cheese

Preparation
Peel the tomatoes and let drain for an hour at least so to remove some of their water, or, if canned, drain well. Heat 2-3 tablespoons of oil over low heat in a earthenware pan.
When the oil is hot put into the cloves of crushed garlic and let wither until browned, take off after being careful not to burn. Pour in coarsely chopped onion and brown for a couple of minutes, add then tomatoes with basil and thyme.
Cook over low heat, adding a little salt (I hate "sweet" sauces), until all the moisture of the tomatoes will be evaporated.
If you want to add the cherry tomatoes, cut them in half and cook in a bit of salted water avoiding to crush if you, like me, prefer them still whole. When ready, drain and add to the sauce.
Cook the spaghetti in salted water. When the water boils, add a tablespoon of oil and pour pasta inside, lowering the heat a bit. Cook pasta "al dente", drain and pour into a large non stick frying pan together with sauce for a minute or two.
Serve pasta sprinkled with grated pecorino cheese.