Sweet Potato Black Bean Vegan Burgers with Fresh Guacamole

Name: Sweet Potato Black Bean Vegan Burgers with Fresh Guacamole
Prep time: 30 min
Cook time: 1 h 15 min
Total time: 1 h 45 min
Yield: 6 servings
Cuisine: Tex-Mex
Ingredients: 1 lb (450 g) sweet potatoes, 2 medium potatoes, scrubbed and pierced several times with a fork; 2 cans (15 oz each) (850 g) canned black beans, drained, rinsed, and well drained again (about 3 cups / 500 g beans); 1¼ cups (115 g) old-fashioned rolled oats, pulsed into a coarse flour; 2 tbsp (14 g) ground flaxseed; 6 tbsp (90 ml) water, cool; ½ cup (75 g) red onion, finely diced (about ½ small onion); 3 cloves (9 g) garlic cloves, finely grated or minced; 2 tsp (4 g) ground cumin; 1 tsp (2½ g) smoked paprika; 1 tsp (3 g) chili powder; 1 tsp (6 g) kosher salt; ½ tsp (1½ g) black pepper, freshly ground; 1 tbsp (15 ml) fresh lime juice; ¼ cup (10 g) fresh cilantro, finely chopped; 2 tbsp (30 ml) olive oil, for brushing the patties; 2 medium (300 g) ripe Hass avocados, halved and pitted; 2 tbsp (20 g) red onion, very finely minced; 2 tbsp (5 g) fresh cilantro, finely chopped; 1 tbsp (15 ml) fresh lime juice; ½ pepper (15 g) jalapeño, seeded and minced (optional); ¼ tsp (1½ g) kosher salt, plus more to taste; 6 buns (390 g) vegan burger buns, split and lightly toasted; 6 leaves (60 g) butter lettuce leaves, washed and dried; 1 large (180 g) ripe tomato, cut into 6 thin slices

From the MyKitchenBank Kitchen

Smoky, cumin-spiced Tex-Mex patties made from roasted sweet potato and black beans, baked until crisp at the edges and tender inside, then piled onto buns with creamy lime guacamole.

Prep: 30 min
Cook: 1 hr 15 min
Wait: 40 min
Total: 2 hr 25 min
Makes: 6 burgers (about 3½ inches / 9 cm wide)

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Ingredients

6 servings

For the burgers
1 lb (450 g) sweet potatoes, 2 medium potatoes, scrubbed and pierced several times with a fork
2 cans (15 oz each) (850 g) canned black beans, drained, rinsed, and well drained again (about 3 cups / 500 g beans)
1¼ cups (115 g) old-fashioned rolled oats, pulsed into a coarse flour
2 tbsp (14 g) ground flaxseed
6 tbsp (90 ml) water, cool
½ cup (75 g) red onion, finely diced (about ½ small onion)
3 cloves (9 g) garlic cloves, finely grated or minced
2 tsp (4 g) ground cumin
1 tsp (2.5 g) smoked paprika
1 tsp (3 g) chili powder
1 tsp (6 g) kosher salt
½ tsp (1.5 g) black pepper, freshly ground
1 tbsp (15 ml) fresh lime juice
¼ cup (10 g) fresh cilantro, finely chopped
2 tbsp (30 ml) olive oil, for brushing the patties
For the guacamole
2 medium (300 g) ripe Hass avocados, halved and pitted
2 tbsp (20 g) red onion, very finely minced
2 tbsp (5 g) fresh cilantro, finely chopped
1 tbsp (15 ml) fresh lime juice
½ pepper (15 g) jalapeño, seeded and minced (optional)
¼ tsp (1.5 g) kosher salt, plus more to taste
To serve
6 buns (390 g) vegan burger buns, split and lightly toasted
6 leaves (60 g) butter lettuce leaves, washed and dried
1 large (180 g) ripe tomato, cut into 6 thin slices

Equipment (7)

Rimmed baking sheet, 18×13-inch (46×33 cm), for the sweet potatoes
Second rimmed baking sheet, 18×13-inch (46×33 cm), lined with parchment paper, for the burgers
Large mixing bowl
Food processor or blender (or a rolling pin and zip-top bag) for grinding the oats
Fork or potato masher
Wide spatula
Small bowl and fork for the guacamole

Steps

Before you start

Preheat the oven to 400°F (200°C) before you start; the same oven temperature is used for the sweet potatoes and the burgers.
Drain and rinse the black beans, then let them sit in a colander for 10 minutes so they are as dry as possible. Wet beans make soft patties.
Plan on about 2 hours 25 minutes from start to table, including baking the potatoes, cooling, and chilling the mixture.
Choose avocados that yield slightly to gentle pressure; if you cannot find ripe ones, make the guacamole last.

1
Roast sweet potatoesOven 400°F / 205°C
- Position a rack in the center of the oven and heat to 400°F (200°C).
- Place the pierced sweet potatoes on a rimmed baking sheet and roast for 45 to 55 minutes, until the skins are wrinkly, a knife slides in with no resistance, and syrupy juices have leaked onto the pan.
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Ready when: A paring knife slides into the thickest part with no resistance
Tip: Line the pan with foil for easy cleanup, since the juices caramelize and stick.
2
Make flax binder
- While the potatoes roast, stir the ground flaxseed and water together in a small bowl.
- Let it sit for 10 minutes until thick and gel-like, similar to a raw egg white.
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Ready when: Mixture is thick and slightly stringy when stirred
3
Prep the base
- Pulse the rolled oats in a food processor 8 to 10 times, for about 10 seconds total, to a coarse flour with some flecks remaining.
- Dice the onion, grate the garlic, and chop the cilantro.
- Make sure the beans are well drained and pat them dry with a clean towel.
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Ready when: Oats look like coarse sand with a few flakes
Tip: Do not over-process the oats into fine powder, or the burgers will turn gummy.
4
Cool and scoop potatoes
- Remove the potatoes from the oven and leave the oven on.
- Cool for 15 minutes, until comfortable to handle.
- Slice each potato open and scoop the flesh into a large bowl, discarding the skins.
- You should have about 1½ cups (350 g).
- Mash until mostly smooth.
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Ready when: Mash is mostly smooth with no hard lumps
Tip: If the mash looks wet or watery, let it sit 5 more minutes; steam escaping makes firmer patties.
5
Mash the beans
- Add the black beans to the sweet potato.
- Mash with a fork or potato masher, crushing about two-thirds of the beans while leaving the rest whole for texture.
- The mixture should look chunky and hold together when pressed.
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Ready when: Mixture is thick and chunky, with about one-third of the beans still whole
6
Season and combine
- Add the flax gel, onion, garlic, cumin, smoked paprika, chili powder, salt, pepper, lime juice, and cilantro.
- Stir well.
- Fold in the ground oats until no dry streaks remain.
- The mixture should be thick, sticky, and hold a shape when squeezed in your fist.
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Ready when: A squeezed handful holds its shape without crumbling or dripping
Tip: If it still feels very wet, add 1 to 2 tablespoons more oats; if crumbly, add 1 tablespoon water.
7
Chill the mixture
- Cover the bowl and refrigerate for 20 minutes.
- The oats absorb moisture as it rests, making the mixture much easier to shape.
- Line a second rimmed baking sheet with parchment paper.
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Ready when: Mixture is noticeably firmer and less sticky
8
Shape the patties
- With damp hands, divide the mixture into 6 equal portions, about ¾ cup (175 g) each.
- Pat each into a round about 3½ inches (9 cm) wide and ¾ inch (2 cm) thick.
- Place on the parchment-lined sheet with 1 inch (2.5 cm) between them.
- Brush the tops with half of the olive oil.
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Ready when: Patties have smooth edges and no cracks
Tip: Rewet your hands often; the mixture is sticky and will cling to dry skin.
9
Bake the burgersOven 400°F / 205°C
- Bake at 400°F (200°C) for 12 minutes.
- Remove the pan, brush the tops with the remaining olive oil, and carefully flip each patty with a wide spatula.
- Bake 12 to 14 minutes more, until the edges are deep brown and crisp and the centers feel firm when pressed.
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Ready when: Edges are deep brown and crisp, and centers spring back when pressed
Tip: Flip only after 12 minutes; earlier, the patties are too soft and may break.
10
Make the guacamole
- While the burgers bake, scoop the avocado flesh into a small bowl.
- Mash with a fork to your preferred texture, leaving some small chunks.
- Stir in the minced onion, cilantro, lime juice, jalapeño if using, and salt.
- Taste and add more salt or lime if needed.
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Ready when: Creamy with small chunks and bright, balanced flavor
Tip: Press plastic wrap directly onto the surface if not serving right away to prevent browning.
11
Rest the burgers
- Take the burgers out of the oven and let them rest on the pan for 5 minutes.
- They will firm up further as they cool slightly and will be much less likely to break when lifted.
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Ready when: Patties lift cleanly with a spatula without bending
12
Assemble and serve
- Set a lettuce leaf on each bottom bun, then add a burger, a tomato slice, and a generous spoonful of guacamole.
- Cap with the top bun and serve immediately while the patties are still warm.
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Tip: The lettuce acts as a barrier that keeps the bottom bun from getting soggy.

Good to know

Tips

Drain and dry the beans well; excess moisture is the main reason veggie burgers fall apart.
Chilling the mixture is not optional, since it makes the sticky mixture manageable and helps the patties hold together.
Use a wide spatula and flip gently once; these patties are tender and need support while hot.
For extra crispness, finish the baked patties for 1 to 2 minutes in a hot oiled skillet over medium-high heat.

Make ahead

"Shape the uncooked patties up to 24 hours ahead, stack between parchment sheets, cover, and refrigerate; add 2 to 3 minutes to the baking time. Roasted sweet potatoes can be baked and refrigerated up to 3 days ahead. Make the guacamole just before serving for the best color."

Storage & reheating

"Room temperature: cooked patties up to 2 hours. Fridge: store cooked patties in an airtight container up to 4 days. Freezer: freeze cooked patties on a tray until solid, then bag for up to 3 months. Reheat from fridge or frozen in a 375°F (190°C) oven for 10 to 15 minutes, or in a skillet over medium heat for 3 to 4 minutes per side. Guacamole keeps 1 day in the fridge with plastic wrap pressed on the surface."

Substitutions

old-fashioned rolled oats → Certified gluten-free rolled oats, or panko breadcrumbs. Use gluten-free oats for a gluten-free burger (and gluten-free buns). Panko works at the same amount but gives a slightly crunchier texture.
ground flaxseed → Chia seeds. Use the same amount of ground chia with the same water; it gels the same way.
canned black beans → Pinto beans or kidney beans. Use the same quantity, well drained. The flavor is slightly milder and the color less dark.
smoked paprika → Chipotle powder. Use ½ teaspoon for a spicier, smokier burger.