1Melt butter in large saucepan on medium heat. Add onion and celery; cook and stir until softened, about 5 minutes. Add cauliflower and stock; bring to boil. Reduce heat to low; add Sauce Mix. Cover and simmer 10 to 15 minutes or until cauliflower is tender. Stir in half-and-half.
2With center part of cover removed to let steam escape, puree soup in batches in blender on high speed until smooth. (Or puree soup in saucepan with an immersion blender.) Heat gently in saucepan before serving, if necessary. Serve warm in soup bowls.