Add 2 tsp olive oil to a pot over medium heat. Add garlic, and red onions, saute for 5 min. Then add the rest of your veggies and saute until they are soft – about 5-10 minutes.
Add pasta sauce to the pot and bring to a simmer. Add dried italian seasoning and salt to taste. Simmer on medium-low heat for 10 minutes until the flavors have combined.
Turn the heat off and blend the sauce with an immersion blender, blending it in “bursts” so that it remains somewhat chunky and doesn’t become completely pureed.