1Heat 1 tablespoon oil in a large non-stick frying pan over high heat. Add the mushrooms. Cook, stirring often, for 4–5 minutes or until tender. Remove from heat. Stand for 10 minutes. Drain excess liquid and place mushrooms in a large bowl to cool.
2Add the mince, onion, Worcestershire sauce and egg to the mushrooms. Season with salt and pepper. Mix well using your hands. Shape mixture into 4 patties. Place on a tray. Cover with plastic wrap and refrigerate for 20 minutes.
3Lightly grease a barbecue plate and preheat on medium heat. Brush the haloumi with remaining oil. Barbecue the patties for 4–5 minutes on each side or until just cooked through. Barbecue the haloumi for 3 minutes on each side or until golden.
4Barbecue the cut side of the buns for 1–2 minutes or until golden. Spread the bun bases with baba ghanoush. Top with patties, haloumi and capsicum. Serve with chips.
Tip: Roasting capsicum yourself is far cheaper than buying it. Place capsicum, skin-side up, on a baking tray. Cook under a hot grill for 6 minutes or until the skin turns black. Place in a snap-lock bag and seal. Stand for 5 minutes (the steam helps lift the skin). Using your fingers, peel the skin (do not rinse under cold water, this dilutes the flavour).