Toss the aubergine together with 2 tablespoons oil and season with salt and pepper. Heat a griddle pan until smoking hot, then cook the aubergine for 3 minutes on each side until charred and soft.
Heat the remaining oil in a saucepan, add the onion and cook over a low heat for 10 minutes until soft. Stir in the garlic, followed by the cayenne, tomato purée and tomatoes. Leave to cook for 5–10 minutes until the tomatoes are lightly charred.
Lay the tortillas on a work surface. Spoon some tomatoes over one half of each tortilla, add some aubergine slices and crumble over some goats' cheese. Fold each tortilla in half, transfer to a baking sheet and place under a hot grill for 2–3 minutes. Carefully turn over and cook for 2–3 minutes more until golden and crispy all over. Cut into wedges and serve.