Put the potato slices into a saucepan of salted water and bring to the boil. Simmer them for 10 minutes until they’re tender but not falling apart. Run some cold water over them after you drain them, to stop them from cooking further.
Meanwhile, heat the oil in a pan and add the sliced leeks and garlic. Cook them, stirring regularly, for around 5 minutes until they’re softened.
Add in the jackfruit and cook for 5 minutes more, stirring often. Then throw in the remaining ingredients- beans, coconut milk, passata and the herbs and spices. Give them a real good stir, then leave it to simmer for 20 minutes.
After 20 minutes, give it a final stir and break up and jackfruit chunks with the back of a spoon. Season the jackfruit pie mix to taste with salt and pepper.
Layer your sliced potatoes on the top and brush them with a little oil, then put it in the oven for 30 minutes until golden brown. Turn the grill on for the last 5 minutes if you want a really crispy top.
Notes
Following this recipe, you should use a cast iron or other stove-to-oven pot. If you don’t have one of these, you can cook the filling in a large pan on the stove, then transfer it to an oven proof pot or dish before adding the potato layer.