This is a general tomato sauce to use with any dishes you like. Pasta, Pizza etc.

Heat up your pot and add olive oil, when oil is hot enough add the pureed onions, pureed garlic, salt and pepper. At this point turn down the stove to medium low so the onions and garlic doesn't burn, now add the Italian seasoning and cook the mixture until is slightly translucent

Now I what your going to say, why don't I just buy the crushed tomatoes or diced tomatoes in a can? I've tried those and for some reason which I can't figure out it's just doesn't turn out the same way with taste and consistancy.

With this part you have choice you can puree the whole tomatoes and add it to the pot or add the cans of tomatoes as they are and use a potato masher to break apart the whole tomatoes for a chunkier sauce, whatever your choice is it's all going turn out great. Now turn down the heat to gently simmer (very important) and add 3/4 cup of water to the sauce. Another important note let the sauce simmer without the lid otherwise the sauce will be to watery

Now let the sauce simmer for 45-60 minutes. At that you should noticed it has thickened up a little. It is now done!!! At this point you should taste and add salt and pepper to taste the way you like it