How to Make It
Melt butter in a large saucepan over medium heat. Add onion and rosemary, and cook, stirring often, 3 minutes or until onion is tender. Stir in flour until smooth. Cook, stirring constantly, 1 minute. Stir in broth until smooth.
Stir in tomatoes, salt, and sugar, gently crushing tomatoes while stirring. Cook 3 to 5 minutes or until just thickened. Discard rosemary. Serve immediately.