In a medium enameled or other nonreactive saucepan, heat 1/4 cup of the olive oil over medium heat. Add the chopped onions, 2/3 of the minced garlic, the chopped celery and chopped carrot and saute until tender, 5 to 7 minutes, stirring occasionally. Add the crushed red pepper and tomatoes and continue to cook, covered, until the tomatoes give up their liquid and begin to fall apart, about 15 minutes. Add the water and orange juice and continue to cook, covered, until the tomatoes have completely broken up, about 15 minutes longer. Season with salt and pepper, to taste.

While the soup is cooking, combine the basil leaves, remaining 2 cloves of garlic, and remaining 1/2 cup of olive oil in a blender and process until very smooth. Season with salt and pepper, to taste and set aside, refrigerated and covered with plastic wrap, until ready to use.

Remove the soup from the heat and puree, in batches, in a blender. The soup may be served either hot or cold – if you plan on serving it hot, return the pureed soup to a clean saucepan and keep warm until ready to serve. If you plan on serving it cold, pour the soup into a heatproof bowl and let come to room temperature, then chill in the refrigerator at least 2 hours and up to 2 days before serving. (Remember to taste the soup and re-season if serving it cold.)

When ready to serve the soup, ladle into bowls and garnish with drizzles of the basil-garlic puree.