Fire Roasted Tomato Soup

Jamie found this recipe and she adapted it to our diet.  I found it very tasty and would definitely make it again whether I was on a diet or not.  She prefers her soup to not be smooth so after pureeing the soup she adds two more cans of fire roasted diced tomatoes.

1 tablespoon I Can't Believe It's Not Butter
1 large onion, chopped (1 cup)
2 cloves garlic, finely chopped
2 cans (14.5 oz each) fire roasted diced tomatoes, undrained
1 can (14 oz) reduced-sodium chicken broth or vegetable broth
2 tablespoons chopped fresh basil leaves, cilantro leaves or Italian (flat-leaf) parsley
1 teaspoon Splenda
1/4 teaspoon crushed red pepper flakes

In 3-quart saucepan, melt butter over medium heat. Add onion and garlic; cook 2 to 3 minutes, stirring constantly, until onion is crisp-tender.

Stir in tomatoes, broth, 1 tablespoon of the basil, the sugar and pepper flakes. Heat to boiling. Reduce heat; cover and simmer 15 minutes. Remove from heat; pour mixture into large heatproof bowl; cool slightly, about 15 minutes.

In blender, place half of the mixture. Cover; blend until pureed. Return to saucepan. Repeat with remaining mixture. Heat over medium heat until hot. Remove from heat. Stir in remaining 1 tablespoon basil.