Sweet Potato Bun Sliders with Portobello, Red Peppers + Pesto “Mayo”

Sweet Potato Bun Sliders | ourfourforks.com

Last week I had leftover basil in the fridge  and, since fresh basil can’t be wasted, I threw it in my Vitamix with some almonds, olive oil and salt: vegan pesto! We ate it all week with spaghetti squash, turkey meatballs, roasted veggies and, since it’s finally starting to feel like summer, on sweet potato bun sliders with portobello mushrooms, roasted red peppers and red onion.


In an effort to eat more whole foods recently, the sweet potato bun has become my favorite substitute for traditional burger buns or sandwich bread. The portobello mushrooms give these sliders some substance while the roasted red pepper, red onion and pesto “mayo” give it that summer barbecue feel. The pesto “mayo,” made by mixing vegan pesto with cashew “mayo,” helps hold the sliders together and elevates the flavor of the vegetables.


Sweet Potato Bun Sliders | ourfourforks.comWHY IT’S HEALTHY// Sweet potato bun sliders are gluten-free, vegan and paleo, made with all whole, natural ingredients. Sweet potatoes are high in fiber and nutrients, including potassium, vitamin A, vitamin C and iron. This vegan pesto is made with cold pressed olive oil, which is full of healthy monounsaturated fat and has been found to lower the risk of heart disease, lower cholesterol levels, and aide in blood sugar control. Basil is extremely high in vitamin K, with 1/2 cup coming close to the 100% of the daily recommended intake. Basil has also been shown to be antibacterial and anti-inflammatory. //


For these sweet potato slider buns, I opted to use the Japanese variety for it’s slightly milder flavor, but any type of sweet potato or yam will work. Since I’m all about portable lunches these days, I’m pleased to report that these hold up perfectly; just wrap in foil or wax paper for a quick lunch on the go.


Sweet Potato Bun Sliders | ourfourforks.comSweet Potato Bun Sliders | ourfourforks.comSweet Potato Bun Sliders | ourfourforks.comSweet Potato Bun Sliders | ourfourforks.com

Sweet Potato Bun Sliders with Portobello, Red Peppers + Pesto "Mayo"
Prep time
Cook time
Total time
Sweet potato bun sliders with a portobello mushroom "burger", roasted red peppers, and pesto "mayo." Paleo, vegan and gluten-free, these sliders are the perfect summer meal.
Recipe type: Entree
Serves: 6-8
For the sweet potato sliders:
  • 1-2 large sweet potato(s) (look for ones thick and round in shape: I used the Japanese variety, with white flesh)
  • 8 small portobello mushrooms, stemmed and ribs scraped out
  • 1 small jar of roasted red peppers
  • 1 small red onion
  • oil (coconut or olive)
  • salt and pepper
For the almond pesto:
  • ½ cup roasted almonds (or sub walnuts)
  • 1 garlic clove
  • 1 cup fresh basil leaves, packed
  • ½ cup olive oil
  • ½ teaspoon salt
  • pepper to taste
For the cashew mayo:
  • ½ cup raw cashews, soaked at least 4 hours
  • ¼ cup water
  • 2 tablespoons fresh squeezed lemon juice
  • pinch of salt
For the sliders:
  1. Preheat the oven to 400 degrees Fahrenheit.
  2. Slice the sweet potato into ¼ inch rounds and arrange on a baking sheet.
  3. Brush or spray lightly with oil, sprinkle with salt and pepper and bake for 25 minutes, flipping after 15 minutes.
  4. On a separate baking sheet, arrange the trimmed and cleaned portobello mushrooms, brush or spray lightly with oil, sprinkle with salt and pepper, and bake for 15-20 minutes until a but shrunken and soft all the way through.
For the almond pesto:
  1. Add all ingredients to a food processor or high speed blender (I used my Vitamix) and blend until smooth.
For the cashew "mayo:"
  1. Add all ingredients to a high speed blender (I used my Vitamix) and blend until smooth.
  1. In a separate bowl, mix the entire batch of cashew "mayo" with 3 tablespoons of the pesto and set aside (see notes about pesto).
  2. Assemble the sliders: place a portobello on top of a sweet potato slice and add some slices of red onion and roasted red peppers.
  3. On a second sweet potato slice, spread about 1 tablespoon of cashew pesto "mayo" mixture and place on top of the slider.
Cashew "mayo" adapted from Detoxinista.

This recipe calls for more almond pesto than you'll need since you'll be mixing 3 tablespoons of it with the cashew "mayo." Keep leftover pesto in the fridge for about a week or freeze for later use. It's great on grilled veggies, spaghetti squash, sandwiches, pizza, eggs, etc.

After baking the sweet potato slices, I used my panini press to lightly "grill" the slices. This is optional, but if you have a panini press it gives the sliders a nice slight barbecued taste.



  1. says

    I just got a bunch of yams today and was thinking they would make amazing mini sliders. Nice to know someone has already tested this! These look incredibly delicious.

  2. says

    I happily stumbled across your website a few weeks ago and I just have to say that I love your recipes, and especially your food photography!
    I’ve started my own only food platform, focused on healthy recipes: Foodness.nl. It’s in Dutch, and it’s going to be one of the largest recipe databases in the Netherlands.

    Half of the recipes on the websites are made and photographed by me, myself and I, the other half is a selection of the best recipes I can find on the web. Your recipe is one of them. I would like to translate the content to Dutch, give you the credits and place a link to your website. This way interested Dutch readers can find more recipes on your website, you will rank higher in Google thanks to my linking in, and because my content is a translation it will not affect your SEO results in Google. I’d like to think of that as a win-win situation.

    Could you please let me know if you like it to be featured on Foodness? We can of course make it a two way deal, where you can use one of my recipes for your website too, under the same conditions. All the recipes that I made myself are added by ‘Claartje’ and listed here: http://foodness.nl/recipe/profile/17/claartje
    I am happy to hear from you!

    With kind regards,

    Claartje Schröder
    Founder of Foodness

    • says

      Hi Barbara – sorry you’re so confused! I made these with Japanese sweet potatoes (as mentioned in the recipe), which have a reddish/purple skin and white flesh. You can read more about them here.
      This recipe will work with any type of sweet potato, though I wouldn’t recommend making this with eggplant – conventional or Japanese. In case you’re curious, Japanese eggplant look like typical eggplant, though longer and skinnier. You can see pictures of those here. Hope that helps!

  3. Naomi says

    The recipe for the sweet potato “buns” says cut them to 16 1/4″ thickness. What size did you really mean? Thanks.

  4. says

    love this, have used sweet potato in so many ways since I love it, but never as a bun substitute, what a wonderful substitution, getting rid of bread for veg and a really powerful anti-oxidant too, thank you for this and also for the pesto!

  5. says

    I’ve tried things like this numerous times with sweet potato and it’s delicious but always ends up so messy to eat because when you bake sweet potatoes they are SOFT and mushy – as they should be. So holding on to them as if they are bread is just really messy and they fall apart as you bite in to any sandwiches you’ve made with them. How do you get around this problem?

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