Digest: sweet potato with savoury vegan marshmallow fluff

This time of year one sees trays of already sweet, sweet potato mixed with even more sugar, a ridiculous amount of spices to mask potato flavor and then smothered in marshmallows and butter.

This is a ‘side,’ apparently.

Can you tell I am not a fan?

I think my resentment of this dish comes not from its flavor (I mean who does not love sweet spiciness with marshmallows, or really anything with marshmallows). I think my resentment comes from what I find to be the unnecessary over-sweetening of an already magically sweet root, the covering over of its subtle umami with too many spices.

This recipe puts a twist on the nostalgic goodness of sweet potato casserole but allows the potato to have a seat at the gathering table, rather than being silenced by pumpkin pie spice blends and brown sugar. The trick is freezing the sweet potato. Yes, freezing it! I promise this extra hour of your cook time is worth it.

Why freeze a sweet potato you ask? Well, by freezing the sweet potato, you drive out some of the excess water, concentrating the sugars. You also lower the starting cook temperature of the sweet potato. This is important because the sweetness of sweet potato comes from a conversion of starches to sugars via an enzymatic reaction. This reaction happens most effectively between 135-170 F. By starting the potato frozen, your potato is at this temperature for longer. This produces more maltose which not only increases sweetness but the umami yum of sweet potato flavor.

That all sounds pretty complex. But, this recipe is super simple. Read on!

blue ceramic plate with a nest of shredded dark greens upon which rests an orange sweet potato that has a fluffy browned topping

sweet potato with savoury vegan marshmallow fluff

Serves two

Ingredients for the potato

  • two medium-large sweet potatoes (about 1lb each)

  • oil of your choosing (I love toasted pumpkin seed)

  • salt

Ingredients for the fluff:

  • 1/4 cup aquafaba

  • 1/4 teaspoon cream of tartar

  • 1/2 teaspoon garlic powder

  • 1/2 teaspoon cinnamon

  • pinch asafoetida (optional)

  • 1/4 cup water

  • 1/2 teaspoon agar powder

  • 3 tablespoons sugar

Method for potato:

  1. One to two hours before cooking, scrub and dry sweet potatoes, poke a few times with a fork, and put in the freezer.

  2. After at least one hour, preheat oven to 450. Remove potatoes from freezer, rub liberally in oil and salt. Cover in foil.

  3. Bake for one hour wrapped in foil. After one hour pull back the foil and cook for a half hour more or even longer until very soft to the touch and shriveled. Let rest.

Method for fluff:

  1. Using a standmixer or handheld mixer with whisk attachment, whisk the aquafaba and cream of tartar for about 3 minutes. Add in spices and whisk until stiff peaks form— about 3-4 minutes more.

  2. In a very small saucepan bring water and agar to a low boil. Cook for about 2 minutes. Add in sugar and cook for 2 minutes more.

  3. Working quickly, immediately pour hot syrup into the aquafaba foam. Mix with the mixer until shiny, about 30 seconds to one minute. The agar will start to set, so this step should not be dallied over.

  4. Slit open the potatoes. Dollop your fluff onto the potatoes. And, then using a small blow torch (or a really big one if you have one— I am kidding do not use a plumber’s torch) caramelize the sugars. Serve with a pile of greens (collards pictured) and some sparkling rose.