Black Bean Burger with Cheddar and Caramelised Onions

Yield: 6 burgers

Ingredients

Burger mixture

  • 400 g (14 oz / about 2½ cups) cooked black beans\
  • Rapeseed or peanut oil, for frying\
  • 65 g (about ½ cup scant) finely chopped onion\
  • 1 tsp mild chilli powder (e.g., piment d’Espelette)\
  • 1 tsp smoked paprika powder\
  • 3 tbsp BBQ sauce\
  • 50 g (2 oz / scant ½ cup) dry-roasted walnuts\
  • 2 tbsp finely chopped fresh coriander (cilantro)\
  • 100 g (about ½ cup scant) boiled black rice\
  • 25 g (about ½ cup scant) panko breadcrumbs\
  • Sea salt

Caramelised onions

  • 2 onions\
  • 2 tbsp butter\
  • 1 tbsp red wine vinegar

To serve

  • 120 g (4 oz) Cheddar\
  • 6 burger buns\
  • Butter for the buns\
  • Cos lettuce

Instructions

  1. Rinse the beans
    Rinse the beans in cold water and drain in a colander.

  2. Cook the onion mixture
    Heat a little oil in a frying pan and fry the chopped onion over fairly high heat until it takes on colour and is on the verge of burning.

  3. Season
    Reduce the heat, add the chilli powder and smoked paprika, and stir. Stir in the BBQ sauce and remove the pan from the heat.

  4. Prepare walnuts
    Roast the walnuts, then chop them.

  5. Mix the burger base
    Put the beans, coriander, rice, panko breadcrumbs, walnuts, and a pinch of salt into a bowl. Mix together using a potato masher so the beans are only lightly mashed. Add the onion mixture and stir until well combined.

  6. Shape and chill
    Take a handful of mixture at a time and shape into 6 round patties by hand or with a food ring. Place on a large plate, cover, and refrigerate for at least 1 hour, preferably longer, so they hold together better during frying.

  7. Cook the caramelised onions
    Peel and chop the onions and place them in a cold saucepan with the butter. Put over medium heat and cover with a lid. The onions will release liquid and cook in their own juices. Stir about every 5 minutes for 30–40 minutes, checking they are not burning. (If they begin to dry out, add the vinegar earlier.)

  8. Finish onions
    Remove the lid, pour in the vinegar, raise the heat, and cook for about 15 minutes, stirring, until considerably reduced. Set aside.

  9. Preheat oven
    Preheat to 180°C (350°F / Gas 4).

  10. Fry the patties
    Heat a few tablespoons of oil in a frying pan over medium heat. Fry the patties for a few minutes on both sides until nicely coloured. Transfer to an ovenproof dish, top each patty with slices of Cheddar, and place in the oven until the cheese has melted.

  11. Toast the buns
    Butter the cut sides of the buns and fry quickly in a pan or toast under the broiler until golden.

  12. Assemble
    Place a patty on the bottom of each bun. Add a cos lettuce leaf and a generous spoonful of caramelised onion. Top with the bun and serve.

Notes

  • Chilling the patties improves their structure and prevents crumbling.\
  • Keep the beans only lightly mashed for better texture.\
  • These burgers freeze well before cooking.