Dice the onion and add to a pot with the olive oil. Saute for 5-10 minutes or until golden.
Add the minced garlic, diced celery and carrot. Saute an additional 10 or so minutes.
Add in the diced bell pepper and zucchini and saute for 5 minutes. Add in the red wine if using and let simmer until the liquid has evaporated.
Add in all remaining ingredients (aside from the basil if using). Cover, reduce the heat to low and simmer for 10 minutes to allow the flavors to blend.
Carefully transfer to a blender with the basil (mine is 64 ounces and can hold everything, but you may need to do this in two batches). Blend until completely smooth. When blending hot liquids, it helps to start the blender on the lowest possible setting and slowly work up, keeping the center part of the lid slightly ajar so heat can escape.
Taste and adjust flavors as desired. I like a little extra red pepper flakes and salt.
Serve with your favorite pasta or let cool and transfer to a jar and store in the fridge or freezer.
If you want to make this more of a creamy tomato sauce, you can blend in 1/2 cup of soaked, then drained and rinsed cashews right into the sauce. You may need to add in a bit of vegetable broth to thin it out.