Brush the eggplants with sunflower oil and grill until golden brown. Meanwhile, cut the onion into rings and quarter the mushrooms.
Put some sunflower oil in the skillet and fry the onion, add the garlic and bake along for 1 minute. Dice the pepper and aubergine and add these to the onions together with the mushrooms. Fry for 10-12 minutes, or until the vegetables are caramelized. Season to taste with salt and pepper.
Grill the buns briefly until golden brown. Rub the bun with the cashew mango and chili cheese and place the sloppy vegan sauce on top. Finish with a sprig of fresh coriander and pickled red onion.