Just like a chocolate or other sweet souffé, you fold in beaten egg whites at the end, just before baking, to get an airy result.
We'd like to take this on a little test run before Thanksgiving, though... Several recipes we found were disappointing. One wasn't a souffé at all (no egg whites!) and another was dusted with powdered sugar (ew).
Below are two promising results. One recipe is from Martha Stewart and is baked in individual ramekins (pictured above) and another is a cauliflower soufflé, which seems to be easier to find than carrot. We think we could simply switch our vegetables.
Get the recipes: