This is my all time favorite soup to make. It's just veggies, salt & olive oil, so I guess it's totally vegetarian / vegan. But I don't really care about that... I just love how it tastes, and that it's such a flexible dish.
I start with tomatoes, red/orange/yellow peppers, zucchini/yellow squash, any kind of onion, and lots of garlic. But you can use eggplant or vary the amounts of any of the ingredients. The only thing I suggest is not using too many green peppers/zucchini because the soup ends up looking a bit brownish. But other than that, use whatever summer veggies you like. Cut them up but not too small. coat with olive oil, and sprinkle sea salt all over it. Roast it at about 375 for about an hour. Toss the veggies a few times to make sure it's all getting evenly browned.
When everything looks good and roasted, I take it out and put it in a stock pot. Add vegetable broth (I've used pacific organic... but again, use whatever you like), and a good bit of basil. Simmer it at medium heat for about an hour... depending on how salty the broth is, you can add more salt or not.
Stir it often, mush up the veggies. When it looks done, mix it in small batches in your blender & return it to the pot.
I like to serve it with fresh bread & cheese. It is soooo good! I like to make a huge pot & freeze individual portions for lunches at work.