1. Heat a large saucepan over medium heat. Add oil; swirl to coat. Add onion and next 5 ingredients (through garlic) to pan; cook 10 minutes, stirring occasionally. Stir in tomato paste; cook 1 minute. Add broth and next 3 ingredients (through tomatoes). Bring to a boil; reduce heat and simmer, uncovered, 30 minutes.
2. Place one-third of tomato mixture in a blender. Remove center piece of blender lid (to allow steam to escape); secure blender lid on blender. Place a clean towel over opening in blender lid (to avoid splatters). Blend until smooth. Pour into a large bowl. Repeat procedure twice with remaining tomato mixture. Stir in cream. Garnish with basil, if desired.