1. Peel the onion, finely slice into rounds and place in a small bowl with the balsamic and a pinch of sea salt. Set aside.
2. Halve, deseed and finely chop the chilli. Trim and finely chop the spring onions and garlic. Halve, deseed and chop the green pepper. Place both in a mixing bowl. Drain the beans and pat dry with kitchen paper. Add to the bowl, along with the breadcrumbs and paprika.
3. Season, mix the bean mixture together with clean hands. Divide into 2 balls, flatten into patties and place in the fridge to chill for 10 minutes you can also (wrap and freeze the spare for another day).
4. In a small bowl, combine half the lemon juice, 1 tablespoon of extra virgin olive oil and the yoghurt. Season well. Mix into the dressing with the rocket. Put aside.
5. Heat 1 tablespoon of olive oil in a non-stick pan over a medium heat. When the pan is hot, fry the burgers for 4 minutes on each side. If they colour too quickly, reduce the heat.
6. Set another pan over a low heat and fry the balsamic onions for 5 minutes or until soft.
7. Slice the tomato and mozzarella into rounds and open the buns.
8. When the burgers are almost cooked, top each one with mozzarella. Cover the burgers with a lid for 2 minutes to melt the cheese.
9. Using the pan for the balsamic onions, put on a low heat, half the buns and lightly toast.
10. Pop slices of tomato on each bun base, and a burger on top. Top with the balsamic onions and Avocado and bun lid. Serve with a side of rocket.
For the Burger :
1 Red onion
1 tablespoon balsamic vinegar
1Fresh red chilli
2 spring onions
1 Garlic Clove
1 x 400 g tin black beans
75g g fresh breadcrumbs
1 Green Pepper
extra virgin olive oil
2 tbsp natural yoghurt
Handful of rocket
2 Ripe beef tomato
75 g mozzarella cheese or Vegan cheese
2 wholemeal buns
For the Guacamole :
Small red onion