JAMIE OLIVER'S VEGETARIAN BLACK BEAN BURGERS

Steps:

• Heat the oven to 400 degrees. Peel and roughly chop 1 onion, then place it in a food processor. Add the mushrooms and pulse until just finely chopped. (Be careful not to overprocess into a paste.) Transfer mixture to a large bowl and wipe out the bowl of the food processor. Add torn bread to the processor, pulse until it forms fine crumbs, then transfer crumbs to the mushroom mixture.
• Add black beans and coriander, season well with salt and pepper, then mix together until thoroughly combined. Divide into 4 equal portions and shape into 1-inch-thick patties. Rub all over with oil and dust with ground coriander, then place on an oiled baking sheet.
• Roast patties until dark and crisp, 35 to 45 minutes. Sprinkle the burgers with the Cheddar. Let burgers cool slightly to firm up. While the burgers cool, transfer the buns to the hot oven and heat for a few minutes until toasted.
• Meanwhile, peel and very finely chop the remaining 1/2 onion. Transfer to a medium bowl. Add the tomatoes. Zest the lime on top, then halve the lime and squeeze lime juice on top, to taste. Add a few shakes of hot sauce and season with salt and pepper to taste. Pit, peel and finely slice the mango and avocado.
• Spread the yogurt on the bases of the rolls or buns, then top with half the salsa, the mango and the avocado. Add the burgers, the remaining salsa, extra Tabasco and cilantro leaves, then pop the lids on, press down lightly and serve immediately.