2 tablespoons all-purpose flour

1 red pepper, seeded and diced

2 1/2 cups corn kernels (about 5 medium ears; reserve corncobs and cut in half)

8 fresh basil leaves

1 tablespoon plus 1 teaspoon tomato paste

4 cups chicken or vegetable broth

1/2 teaspoon crushed red chili flakes, or more to taste

Salt and pepper to taste

1/2 cup cheese croutons, for garnish

1/4 cup sour cream, for garnish

Basil sprigs, for garnish

1. In a large soup pot heat the olive oil on medium heat. Add the leeks and saute for about 5 minutes or until softened. Add the tomatoes and cook for 3 more minutes or until slightly softened. Add the flour and stir with a wooden spoon, making sure that the flour is dissolved. Continue cooking for 2 more minutes, or until flour is well blended into the vegetables.

2. Add the red pepper, corn kernels, basil sprigs, tomato paste, chicken stock, chili flakes and corncobs, and bring to a simmer. Simmer for about 25 minutes or until all the vegetables are nicely softened, partially covered. Remove the corncobs and discard.

3. Puree the soup using either the hand blender or the food processor with the metal blade. Pour the soup through a fine mesh strainer into a large container. (If you have a Vitamix, the soup will be blended into a smooth puree and no straining is needed.) Add salt and pepper and taste for seasoning. Bring to room temperature and then refrigerate for at least 4 hours.

4. To serve: Ladle the soup into a soup bowls and place a few croutons on top. Place a spoonful of sour cream on top of the toast and then garnish each toast with a spoonful a basil sprig.

(Diane Rossen Worthington is an authority on new American cooking. She is the author of 18 cookbooks, including "Seriously Simple Parties," and a James Beard Award-winning radio show host. You can contact her at www.seriouslysimple.com.)