Vegan black bean burger

Name: Vegan black bean burger
Cook time: 1 h
Total time: 1 h
Cuisine: American
Ingredients: olive oil; 400g tin black beans rinsed and drained well; 100g from a pouch cooked brown rice; 1 onion finely chopped or grated; 1 tsp fennel seeds crushed; ½ tsp garlic salt; 1 tsp smoked paprika; 25g panko breadcrumbs; finely chopped to make 1 tbsp flat-leaf parsley; 2 tbsp red wine vinegar; 2 tsp golden caster sugar; 1 red onion finely sliced; 100g silken tofu; 1 tsp cider vinegar; 1 tsp lemon juice; a pinch English mustard powder; 1 tsp chipotle paste; 1 avocado peeled and stoned; 1/2 small red onion finely chopped; 1/2 red chilli finely chopped; chopped to make 1 tbsp coriander; 1/2 lime juiced; 4 vegan or regular buns halved; curly lettuce leaves; beef tomato slices; ketchup; mustard