Drain the jackfruit, rinse it thoroughly and pat dry. Cut it into thin slices.
Put the oil into a large non-stick pan and place over a high heat. Add the jackfruit and stir-fry for 5–7 minutes, until it begins to colour. Add the garlic, paprika and cumin and fry for another minute until aromatic. Reduce the heat to medium, add the soy sauce, maple syrup, vinegar and tomato purée and simmer for another 3–4 minutes, stirring frequently, until all the liquid has reduced down and the jackfruit has thickened and become sticky. Taste and adjust the seasoning if necessary with salt and pepper.
To serve, place some lettuce on the base of a burger bun, top with vegan cheese, if using, slices of red onion, tomato and the jackfruit. Place the other half of the bun on top and serve immediately.