Greek salad with phyllo triangles and tzatziki

Ingredients

• 3 phyllo pastry sheets, cut into 5cm strips
• 45ml (3 tbsp) butter, melted
• 125ml (½ cup) feta, crumbled
• 250ml (1 cup) Greek yoghurt
• 1 cucumber, peeled, seeded and grated
• zest of 1 lemon
• 5ml (1 tsp) garlic, finely chopped
• 5ml (1 tsp) ground cumin
• salt
• freshly ground black pepper
• 15ml (1 tbsp) oregano, finely chopped
• 30ml (2 tbsp) lemon juice
• 15ml (1 tbsp) whole-grain mustard
• 60ml (¼ cup) olive oil
• 4 tomatoes, cut into wedges
• 125ml (½ cup) black olives
• 2 small cucumbers, halved, seeded and sliced
• 2 red onions, cut into wedges
• 200g grilled lamb, sliced