Dice the yellow onion and mince the garlic.
Heat a large pot or Dutch oven over medium heat.
When the pot is hot, add the olive oil and then the onion. Continue to sauté until the onions are translucent.
Add the garlic and sauté for another minute.
Add the remaining ingredients except for the fresh basil to the pot and bring to a simmer.
Allow the pasta sauce to continue to simmer for at least an hour.
Using an immersion blender, blend the sauce until it is smooth.
Add the fresh basil and allow the sauce to cook for another 15-30 minutes.
Serve with your favorite pasta or use as a pizza sauce.