4 large Portobello mushrooms
30g/1oz fresh coriander, very finely chopped
2 large garlic cloves, crushed
salt and freshly ground black pepper
2 tbsp olive oil
2–3 tbsp pine nuts, finely chopped
50g/1¾oz unsalted butter, softened
125²µ/4½´Ç³ú halloumi, coarsely grated