Yes, that looks very similar to the pizza sauce I make. There´s no need for onions, to be honest, although if you want to add them, fine. All you need to do while the sauce is cooking is to mash it down with a potato masher, so it gets thicker and breaks up the whole tomatoes. If you decide to blend it to a paste, then fine, too. IF you can find fresh oregano and basil, then it is preferable.Would you use this recipe for tomato sauce? Interesting that it doesn't have onions.
The only thing I´d leave out for an Italian pizza sauce is the chile powder; but since the blogger is Indian, I fully understand!