Gather your tools and ingredients and start by preparing your onions and garlic.
Place a large soup pot on the stove over medium heat. Add the olive oil and then the garlic and onion. Sauté, stirring occasionally while you chop the carrots and celery stalks. When the onion mixture is beginning to brown, add the dried oregano, dried basil and red pepper flakes, stir in with the onions and garlic for about 1 minute. Next add the carrots and celery and cook for about 10 minutes, stirring occasionally. Carefully add the tomatoes and the water. Bring to a boil, stir again and then reduce the heat to a simmer. Allow it to cook with the lid on for another 20 minutes or until the vegetables are tender.
Remove the pan from the stove and season with salt and pepper.
With an immersion blender, puree the soup or carefully ladle it into a regular blender. If using a regular blender, only fill it half way full and cover the blender with a towel. Turn on low speed to avoid it splattering hot soup.
Serve and top with fresh basil.