Heat oil in a large saucepan over medium heat; add cauliflower, onions, and 1/4 teaspoon salt. Reduce heat to medium-low; cover. Cook until onions are softened, stirring occasionally, about 8 minutes. Add corn and garlic; cover. Cook 4 minutes; add Swanson(R) Chicken Broth and remaining 1/2 teaspoon salt. Increase heat to medium-high; bring to a boil. Remove from heat.
Place half of corn mixture in a blender. Cover and hold lid down; pulse a few times before leaving on to blend. Blend until smooth. Repeat procedure with remaining corn mixture. Chill at least 4 hours.
