Tomato Sauce

There is a short scene in The Godfather where Peter Clemenza gives Michael Corleone tips on what he should do in case he ever has to cook for 20 guys.  According to Francis Ford Coppola's commentary, he included the scene so that, in case the film was a flop, viewers would at least learn how to make a decent tomato sauce.  Well, it turns out Francis Ford Coppola got it backwards.  The Godfather turned out to be a huge hit spawning a great sequel (1), but now seemingly everyone buys their tomato sauce in jars at the supermarket.  To me, this is a little crazy.  Making tomato sauce at home is very easy and considerably cheaper and healthier than buying it.

I don't usually follow the recipe described in The Godfather because I don't usually follow any recipe.  In my opinion, the best way to make a good tomato sauce is to make it the way you like it with whatever you have on hand.  I've written out how I make a very basic sauce (with some notes about additions where applicable), but I wouldn't argue with anyone who does it differently.

This recipe is sufficient for 4 or servings depending on how many things you decide to add.

You will need:
14oz canned tomatos (crushed or whole)
1 onion
4 cloves garlic
2 teaspoons olive oil
2 teaspoons oregano
salt
pepper

You can add:
6 italian sausage links
1 roasted bell pepper
1/2 cup fresh basil
1 head of roasted garlic
1 liberal splash of red wine

Steps:
1.  Heat the oil in a medium sized pot.  When oil is heating, dice onion and garlic.  Cook onions then garlic over medium heat until onions are translucent (2).
2.  Pour crushed tomatos into the pot, stirring to integrate garlic and onion.  Season with oregano then salt and pepper to taste (3).
3.  Cook for about 20-30 minutes over medium heat, stirring occasionally.  The sauce will be done when the tomatos have mostly disintegrated into sauce form (4).  Serve over pasta.

Notes:
1.  Shame that third Godfather movie never got made.  Oh well.
2.  If you decide to use roasted garlic, you don't need to add garlic at this stage.  Instead add the roasted cloves when you pour in the tomato.  Of course, you could also add garlic at both stages if you really love garlic (who doesn't) or really hate vampires (who doesn't).  If you are adding meat to the sauce, add it when the onions are translucent and brown the meat before adding the tomato.
3.  Add in the (chopped) roasted pepper at this stage.  Roasting a pepper is easiest with a gas stove and a pair of tongs, but you can also just place it in a heated pan, flipping occasionally.  If you are adding wine (and I only do when I have some on hand, which is not often) add it at this stage.  Don't add a wine you wouldn't drink and don't add too much.
4.  For best results make the sauce the day before serving and then reheat when you are making pasta.  If you decide to add it, mix in fresh basil immediately before serving.