Seasoning each component really well in this vegetarian sandwich, will make everything pop—as will the lemony garlic mayonnaise.

Ingredients

1 large sweet potato (about 12 oz.), peeled, sliced lengthwise into 1/4"–1/2"-thick planks

1 tsp. ancho chile powder

1/2 tsp. ground cumin

3 Tbsp. extra-virgin olive oil, plus more for drizzling

1 medium beet, peeled, cut into thin matchsticks or grated on the large holes of a box grater

1/2 small red onion, thinly sliced

3 Tbsp. seasoned rice vinegar

1/2 cup mayonnaise

1 large garlic clove, finely grated

1 Tbsp. plus 1 tsp. fresh lemon juice

2 sesame kaiser rolls, split

1 1/2 cups parsley, mint, and/or cilantro leaves

5 oz. block feta, thinly sliced into planks, divided

Kosher salt, freshly ground pepper

Step 1
Preheat oven to 400°F. Combine sweet potato, ancho chile powder, cumin, and 3 Tbsp. oil in a medium bowl; season generously with salt and pepper and toss until sweet potato is evenly coated. Heat a dry large skillet, preferably cast iron, over medium. Arrange sweet potato in a single layer without overlapping (you will most likely be able to fit them all at once, but work in 2 batches if needed). Cook, undisturbed, until blackened in spots, about 4 minutes. Turn slices over and transfer skillet to oven. Roast until tender, 10–15 minutes. Remove from oven.
Step 2
Meanwhile, combine beet, onion, and vinegar in a medium bowl; season generously with salt and pepper and toss well. Let sit to allow beet to soften. Mix mayonnaise, garlic, and 1 Tbsp. lemon juice in a small bowl; season generously with salt and pepper.
Step 3
Heat broiler. Toast rolls, cut side up, on a rimmed baking sheet until golden brown, 30–60 seconds. Remove rolls from oven.
Step 4
Toss herbs with remaining 1 tsp. lemon juice in a medium bowl to coat. Drizzle with oil, season with salt and pepper, and toss again to combine.
Step 5
To build sandwiches, pour off any accumulated liquid from beet mixture. Spread seasoned mayonnaise over cut sides of reserved rolls, dividing evenly (yes, it’s a lot, but you don’t want to skimp here). Arrange feta slices over bottom halves of rolls. Top with sweet potato slices and pile some beet mixture on top. Mound herbs over beets; close up sandwiches with top halves of rolls and cut in half.
Do Ahead
Step 6
Sweet potato, beet mixture, and seasoned mayonnaise can all be made 2 hours ahead. Store sweet potato and beet mixture separately, tightly covered, at room temperature. Cover and chill mayonnaise.

Leave a Review

Reviews (10)

Great color, textures and flavors! I’ve made this twice. The second time, to speed it up on a weeknight, I skipped the dry skillet step and only roasted the sweet potatoes using a big sheet pan.
- Anonymous
- 7/13/2023
Great flavor--worth the effort. If you make the beet and red onion as a chutney ahead of time (and for additional use), it's not as much work.
- liz002
- Hobart, NY
- 5/4/2021
Delicious and flavorful. The garlicky mayo is key! We used potato buns because that's all we had - worked fine but probably would be better with something sturdier. My notes for next time: would use a higher heat oil (EVOO seems wasted as the pan became smoky) and I would try tossing the spices on the sweet potato after charring it (before putting in oven, might also add some olive oil at that point).
- Anonymous
- Boston
- 1/24/2021
Absolutely delicious! Fresh and impressive flavours and textures. All the meat eaters exclaimed they did not ‘miss ‘ the meat at all! Chose a panini bun from my local bakery instead of a Kaiser (personal preference). Looking forward to making this again and again.
- cookinvictoria
- BC
- 12/7/2020
These are so good, and so easy. Once you make them a few times you realize they only take a bit of time to chop, everything else is simple. Really great recipe for meal prep too. I’ve shared this with my whole family.
- carladhu
- Arizona
- 10/6/2020
this sandwich is fantastic! the smooth sweet potatoes, the spicy crunchy beets, the garlicky mayo.
- s.stiles8871
- new jersey
- 10/5/2020
Wow! Ok it’s super labor intensive, I used Mexican Cojita cheese instead of Feta. I literally wanted to write an ode to my food while I was eating it! It’s was one of the best sandwiches I have ever had, I will be spending another 1 1/2 hours making it again! Lol
- Zazadance
- San Francisco
- 9/25/2020
Delicious, hearty veg sandwich. I used flat leaf parsley for the greens but should have added more to crisp, lighten it up. It is rich with the mayo, potato and cheese so needs the greens!
- ritajoyholmberg6443
- Vancouver, BC
- 6/10/2020
This was fantastic. I did change it up a bit, but I can't imagine this not being great as is. My new fave!
- ncm209
- southofboston
- 12/9/2019
I was a little worried about so many strong flavors placed together. My concern was for naught, as this was so pleasantly delicious and refreshing! The only ingredient I didn’t include (and that is because I was certain I had it but when I started my mis en place, I didn’t) was cumin. I will definitely make sure to include this next time. I recommend this to everyone!
- stecgra9189
- Salt Lake City
- 4/6/2018
Yummmmmmmmmm
- Anonymous
- 1/17/2023