Truffle flavored Roasted Japanese Sweet Potatoes with Black Lava Salt

Jewel yam slices with truffle oil on plate with crab cakes and lettuce

The above photo was our dinner tonight: vegan crab cakes (from the brand Sophie’s Kitchen, really tasty), roasted red pepper remoulade, and –the recipe I’m going to share with you tonight– roasted Japanese Sweet Potato slices flavored with truffle oil and black lava salt.

Before anyone raises the question as to whether or not (good) truffles are vegan due to their being harvested almost exclusively using dogs or pigs, I have to tell you that almost all truffle oil has never had a truffle anywhere near it. The vast majority of truffle oil is flavored synthetically. So no debate needed!

While this plate looks fancy, it’s actually a quick, simple dinner. It all came together in under an hour. And most of that hour I spent on the internet looking at other Vegan MoFo posts.

This is mostly due to the fact that the crab cakes were pre made. All I did was brown them on both sides. The remoulade I made is still “in development.” Which is code for “I don’t actually know what I did, but it was awesome.” Which is the reason the only recipe I’m going to share is the side dish.

What the food hole had labeled as “Jewel Yams” (hence my instagram teaser yesterday) are actually Japanese Sweet Potatoes. They have a ruby red skin and creamy, white flesh.  Their flavor isn’t as pronounced as the bright orange sweet potatoes common around Thanksgiving. Rather, the Japanese sweet potato has a more delicate flavor with a slight sweetness. And in this case, that made an amazing canvas for truffle oil.

This recipe uses two ingredients that aren’t always readily available, truffle oil and black lava salt. Black lava salt is really just used as a contrasting garnish here. You can finish the dish with whatever salt you have and it will taste the same. You could even sprinkle some black sesame seeds on top and get a very similar visual effect. If you can’t get your hands on truffle oil, however, that’s another story. You can try any other infused oil –like garlic or rosemary– but, obviously, you won’t get that truffle flavor without it. Experiment, let me know if there are other flavored oils that work well here.

Truffle flavored Roasted Japanese Sweet Potatoes with Black Lava Salt


  • 1 large Japanese sweet potato
  • 2 cloves garlic
  • 2 Tablespoons olive oil
  • sea salt
  • 2 teaspoons truffle oil
  • black lava salt


  1. Sliced, fanned sweet potatoes on baking sheetPreheat oven to 400 degrees Fahrenheit and line a baking sheet with parchment paper.
  2. Slice the potatoes 1/8 inch thick. Try to keep slices next to each other and in the same orientation. It will make for a prettier finished product. Arrange about half of the slices (15 to 20 ish) on the baking sheet. Fanning them out in a line as shown in the photo. Repeat with the second half of the potato.
  3. Peel the garlic cloves and slice each very thinly, trying to get as many slices out of the two cloves of garlic as you got out of the potato. Tuck a garlic slice between each slice of potato (or nearly every slice).
  4. Drizzle each potato fan with a tablespoon of olive oil and sprinkle them with sea salt.
  5. Roast for 35 to 45 minutes, or until the center is tender and can be easily pierced with a knife.
  6. Transfer to the serving plate by sliding a long, offset spatula under each portion and carefully placing it on the plate. Note: The bottom potato slice on each stack may appear darker than all the others. You may choose not to serve that slice due to it’s appearance, it’s up to you.
  7. Drizzle each portion with a teaspoon (or a little more if you like) of truffle oil. Sprinkle the top with some black lava salt as a garnish. Serves 2.

For the record… Japanese Sweet Potato + Truffle Oil = HOLY CRAP DELICIOUS!!!!!

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