I use a simple secret that save some fat from your sauce too: fry in the frying pan the onion, a bit of extra virgin olive oil and a little of water.
When it dries, you add a more water- a couple of spoons. In this way the onion did not burn but instead cook completely and become very soft.
When it is ready, you add the other ingredients. It’s a matter of just 5 preliminary minutes for a very good sauce.
Onion soffritto is required for the pasta sauces with: