Whether you’re making a smooth vegetable soup or a vegan “cheese” sauce, a blender is a must for getting a great sauce with no dairy. Immersion blenders are the easiest to use, as they can be dropped right into a pan of hot soup. If you’re attempting a partial puree, which can add body while leaving chewable pieces in a soup or stew, immersion blenders can be a little too good at their job. In those cases, removing part of the soup to a blender and stirring it back in might be a better option.
Remember that hot liquids and blenders do not easy bedfellows make, though, and take appropriate safety precautions! Never seal hot liquid in a blender jar: always leave it ventilated to allow for expansion of hot air. Leave the vent hole open. Cover it loosely with a clean kitchen towel to prevent messes.