Preheat your oven. I don’t really set the temperature; I turn it on to the maximum setting.
Slice the tomatoes and onions into rings, the red bell pepper into thin slices, and the garlic into halves. Take care not to thinly slice the onions or garlic since they burn very quickly.
Spread everything on an oven tray or Pyrex, drizzle some olive oil and sprinkle the peppers and herbs.
Place the tray in an oven for 30-45 minutes but make sure to check on it every once in a while after the first 20 minutes have passed. The tomatoes would have released their juices at that point so stir the ingredients if they look like they’re drying out and the juice from the tomatoes will prevent sticking.
While everything is roasting in the oven, boil one glass of water (or a bit more in case you like your soup thinner)
When everything is browned and aromatic, take it all out of the oven, dump all the ingredients in a blender along with the boiling water and blend until smooth. I like mine very thick but feel free to add more water if you like yours lighter.
Transfer to a bowl and drizzle with balsamic vinegar (optional) and herbs. Serve with bread or crackers, or even better a light green salad!