The key to making a flavorful, tender butternut squash soup

This undated photo provided by America's Test Kitchen in September 2018 shows creamy butternut squash soup in Brookline, Mass. This recipe appears in the cookbook “All-Time Best Soups.” (Carl Tremblay/America's Test Kitchen via AP)

This simple butternut squash soup is little more than squash, cooking liquid, and a few aromatic ingredients; it comes together easily yet is creamy and deeply flavorful.