Heat the oven to 180°C/350°F. Heat the oil in a pot over a medium heat, add the onion and garlic and cook until softened. Break up any bigger pieces of jackfruit and add to the onion with the spices and chipotle paste and stir to coat.
Add the vegetable stock and tomatoes and bring to a simmer, cook until the jackfruit has broken down, about 30 minutes. Line a baking sheet with baking paper and spread the jackfruit on it. Put in the oven for 20 minutes.
Serve in warmed tortillas with toppings of your choice.
Nutrition information is an estimate and will vary depending on the exact ingredients used.