Drizzle a little olive oil in frying pan over a medium high heat.
Add the onion and fry till softened and translucent.
Add the garlic and fry for a further 2 mins.
Add the tomatoes, splash of red wine vinegar and a little bit of stock and simmer away, stirring ever now and then.
As the stock reduces down, keep adding a little more, you want to keep doing this, until the tomatoes break down and become more sauce like.
While the tomatoes are cooking, you can cook the spaghetti, add it to a pot of boiling hot water seasoned with a little salt and cook till al dente (approx 7-10 mins)
When sauce is ready, add the spaghetti into the sauce with a couple of ladles of the pasta water and stir to coat the pasta in all the sauce.
Season with a little black pepper, and a sprinkle of fresh chopped Italian parsley.
Serve topped with shavings of Parmesan cheese (omit if dairy free)