Cut the tomatoes and onions into uniform wedges so they roast evenly.
Place the cut tomatoes and onions onto a baking sheet with the garlic cloves and mix with the dried herbs.
Roast the tomatoes for 40-45 minutes until they're shriveled, slightly charred, not burnt.
Blend the roasted veggies in a blender with the veggie broth and add to the pot OR use a spatula to transfer the roasted veggies to your pot and then cover with the vegetable broth and blend with an immersion blender in the pot.
Bring the blended soup to a boil and then simmer the soup on the stove for about 20-30 minutes to cook the tomatoes with the broth.
Season the soup with salt and pepper to taste and stir in chiffonade basil leaves.