Spiced sweet potato and chickpea burger

Instructions

1. 1 Preheat the oven to 180°C. Arrange the sweet potato pieces on a baking tray, in a single layer. Drizzle with a tablespoon of oil, shake to coat, then roast in the oven for approximately 30 minutes until soft and golden. Take out and leave to cool slightly, leaving the oven on.
2. 2 While the sweet potatoes are in the oven, heat 2 tablespoons of the oil and fry the diced onions until tender and beginning to caramelise.
3. 3 Reduce the heat, then add the chickpeas and the BBQ & Meat spice blend. Fry for couple of minutes, until the onions are fragrant and well-coated.
4. 4 Transfer the mixture into a bowl, and mash into a coarse purée with a wooden spoon.
5. 5 Take half of the sweet potatoes and blend in a food processor. Combine the sweet potato puree with the remaining sweet potatoes, then add to the bowl with the onion and chickpea mixture. Add cornflour and salt to taste. Mix well.
6. 6 Divide the mixture into 6 portions and form patties in a burger press, or between your hands. Heat the remaining 2 tablespoons of oil on the pan and fry each patty for 2 minutes on each side.
7. 7 Cut the burger buns into halves and toast them in the oven for 2 minutes at 180°C. Spread a dollop of seaweed aioli (or mayo) on each half of bun, then assemble the burger. We like put the lettuce and gherkins underneath the patty, and the onions and tomatoes on top.