Swirl olive oil into a shallow, wide-bottomed pan with sides. Heat over medium low.
Quarter tomatoes, and remove any larger cores. If tomatoes are very large, cut in sixths or eights. No need to remove small cores. If using cherry or grape tomatoes, cut in half. Add to pan along with salt, pepper, and garlic powder. Increase heat to medium.
Dice onions, and peel garlic. Add onions to pan and using a garlic press, press garlic into pan. Stir to combine, and continue to stir frequently throughout cooking process.
Chop basil and any other fresh herbs you are using. Add fresh herbs (and/or dried) along with balsamic vinegar to pan. Stir to combine.
If using, dice fresh cayenne, and add to the pan (add crushed red pepper flakes here if using).
Stir in red wine if using, and turn heat to medium-high. Make sure to frequently stir to prevent burning.
Cook about 12-15 minutes until sauce just begins to hold a bit to the bottom of the pan when stirred. If using, whisk in flour and cream until blended and lumps are gone.
Stir 1-2 more minutes to cook flour, and then remove from heat.