To make the mango ketchup: Peel and very finely dice the onions, garlic and ginger. Deseed and chop the chilli peppers. Fry the onions, garlic, ginger and chilli peppers in 2 tablespoons of oil. Add the maple syrup and apple cider vinegar and boil. Cut the mangos in half, remove the stone and peel away the skin. Finely dice the mango, add to the onion mixture and simmer for 20 minutes. Purée until smooth and season to taste with the crushed mustard seeds, curry powder, salt and pepper. Pour the mixture into clean glasses while still hot and allow to cool.
To make the courgette and halloumi parcels: Wash and clean the courgettes. Using a grater, shred the courgette lengthways into thin slices, sprinkle with salt and steep in water for 20 minutes. Dab off the water and sprinkle the courgette slices with some wholemeal flour.
Cut the halloumi into cubes (roughly 1.5 x 4.5 cm). Lay 3 or 4 courgette slices crossways one on top of another and place a cube of halloumi on top. Fold over the courgette strips to form a ‘parcel’ and secure using a wooden skewer; repeat as necessary. Heat the olive oil in portions in a griddle pan and fry the parcels on one side and then on the other for a total of 6 minutes. Season with salt and pepper, sprinkle with chilli flakes and serve with the mango ketchup.