Bean & Oat Burger with Cajun Mayo

Ingredients

• 2 tbsp (about 14 g)ground flaxseeds
• 60 ml (¼ cup)water
• 5 ml (1 tsp)olive oil
• 1 mediumonion
• 3 clovesgarlic
• 255 g (1½ cups)cooked pinto beans
• 45 g (⅓ cup)roasted sunflower seeds
• 60 g (¾ cup)rolled oats
• 1 tbsp (about 8 g)nutritional yeast flakes
• ½ tbsp (about 4 g)ground cumin
• ½ tbsp (about 4 g)sweet paprika powder
• 2 tsp (about 5 g)Cajun seasoning
• 5 ml (1 tsp)olive oil
• 280 g (9.877 oz)button mushrooms
• 2red bell peppers
• 3 tbsp (45 ml)chipotle adobo sauce
• 120 ml (½ cup)vegan mayonnaise
• 2 tsp (about 5 g)Cajun seasoning
• 6burger buns
• 20 g (1 cup)rocket
• 100 g (1 cup)coleslaw
• 40 g (¼ cup)pickled jalapeños

Instructions

1. 1

   Gel the flax

   Mix the ground flaxseeds and water in a large bowl, then leave the mixture to thicken.

2. 2

   Cook the onion

   Heat the oil in a sauté pan over a high heat. When hot, add the onion and garlic and cook until golden. Transfer them to the bowl with the flax mixture.

3. 3

   Cook the mushrooms

   Put the empty pan back on the hob and sauté the mushrooms in the oil over a medium-high heat for 5 minutes.

4. 4

   Add the peppers

   Stir in the bell peppers and chipotle adobo sauce, then cook for a further 3 minutes. Set aside.

5. 5

   Mix the patties

   Add the remaining patty ingredients to the bowl. Mash everything together with a fork, then set the mixture aside.

6. 6

   Make the mayo

   Put the vegan mayonnaise and Cajun seasoning in a bowl and mix well.

7. 7

   Shape the patties

   Scoop a heaped ½ cup of the bean mixture into your hands and shape it into a patty. Repeat with the remaining mixture.

8. 8

   Fry the patties

   Heat some oil in a large non-stick pan over a medium-high heat. Cook the patties for 3 to 4 minutes per side, until lightly golden.

9. 9

   Assemble the burgers

   Serve the patties in burger buns with coleslaw and the sautéed mushroom and pepper mixture. Finish with Cajun mayo, rocket and jalapeños.

What is a bean and oat burger?

This is a plant-based take on the familiar burger, built around a patty made from pinto beans, oats and sunflower seeds. Bean burgers draw on a broad tradition of meat-free patties, while this version adds Cajun seasoning and smoky chipotle vegetables for a bold, savoury finish.

Flax mixed with water helps bind the patty mixture, and the oats give it body. The contrasting toppings bring heat, freshness and crunch to the soft bun.

Nutrition and macros by portion

The nutrition label shows one serving as written: 452 calories, 16g protein, 65g carbs, 16g fat.

The buns, oats and beans provide most of the carbohydrates, while the olive oil, sunflower seeds and vegan mayonnaise contribute much of the fat. Pinto beans and sunflower seeds also supply protein. For a more balanced plate, serve a burger with a generous side of salad or extra vegetables.

Getting the patty mixture right

Flax binder: give the ground flaxseeds and water time to gel before adding the other ingredients. This helps the mixture hold together when shaped and cooked.

Texture: mash with a fork rather than blending everything smooth. Leaving some beans and seeds intact gives the patties a more substantial bite.

Building smoky vegetables

Mushrooms: cook them first in a hot pan so they sauté rather than sit in liquid. The recipe gives them 5 minutes before the peppers go in.

Chipotle: add the adobo sauce with the peppers and cook for a further 3 minutes. Keep the pan moving occasionally so the vegetables cook evenly.

Shaping and cooking the patties

Portioning: use a heaped ½ cup of mixture for each patty, as directed, and press it into a shape that will fit your buns. If the mixture feels loose, handle it gently as you transfer it to the pan.

Doneness: cook for 3 to 4 minutes on each side over a medium-high heat. Look for a lightly golden surface before turning; the patties should stay intact when you flip them.

Timing the components

Prepare the flax binder first, then cook the onion and garlic while it thickens. Once the mushroom and pepper mixture is set aside, shape and fry the patties and mix the mayo.

The listed total time is 45 minutes. Keep the vegetables aside while you cook the patties so they are ready to assemble together.

Serving the burgers

Layer each bun with coleslaw, a patty and the warm mushroom and pepper mixture, then add Cajun mayo, rocket and pickled jalapeños. The creamy sauce and crisp toppings balance the savoury bean filling.

Serve straight away, while the patties and vegetables are warm. A simple side salad or extra coleslaw makes an easy accompaniment.

Recipe notes & tips

• Let the flax and water stand until the mixture has thickened before adding the patty ingredients.
• Mash the beans with a fork so the mixture retains some texture.
• Cut the mushrooms and peppers into similar-sized pieces for more even cooking.
• Use a non-stick pan and turn the patties gently to help them stay together.
• Mix the Cajun seasoning thoroughly into the vegan mayonnaise before serving.
• Add the jalapeños at the end so their sharp, pickled flavour stays distinct.

Variations

• Adjust the heat: use fewer pickled jalapeños for a milder burger.
• Change the greens: use baby spinach instead of rocket.
• Add fresh herbs: mix chopped coriander into the coleslaw.
• Boost the smoky flavour: add a little more chipotle adobo sauce to the vegetables.
• Swap the beans: use cooked black beans in place of pinto beans.
• Make it gluten-free: use suitable gluten-free oats and burger buns.

Common mistakes to avoid

• Skipping the flax resting time: leave it until it gels so it can help bind the mixture.
• Over-mashing the beans: stop while some beans and seeds are still visible for a less uniform texture.
• Crowding the pan: cook in batches if needed so the patties can brown rather than steam.
• Turning too soon: wait for a lightly golden surface and flip carefully.
• Adding the toppings too early: assemble just before serving to keep the buns from becoming soggy.

How to store

Store leftover cooked patties and the vegetable mixture separately in airtight containers in the fridge for up to 3 days. Reheat them in a pan until hot, and assemble with fresh buns and toppings just before serving.

Frequently asked questions