Drain the beans and put in a blender together with the breadcrumbs, egg, chipotle paste, spring onions and lime zest. Season with salt and pepper, then whiz until you get a coarse mixture.
Shape 4 equal sized balls from the mixture, then press them slightly between your palms.
Put the patties on a plate, cover and rest in the fridge for 20 minutes or until needed.
Make the salsa: cut the peppers into small cubes, scatter them onto a baking tray and drizzle with the oil. Grill or roast in the oven for 15 minutes, then add the tomatoes and bake for a further 5-10 minutes. Transfer the mixture and the cooking juices into a bowl, season with salt and pepper, and add the juice of the lime and the chilli flakes. Toss and set aside.
Heat some oil in a frying pan and cook the patties for 5 minutes on each side, or until golden brown.
Meanwhile warm or toast the tortilla wraps.
Fill each tortilla with some lettuce, salsa and a patty.