To make the lamb patties, combine ingredients in a bowl, season to taste and mix well with your hands to combine and until the mixture starts to hold together. Divide into four and shape each into a flat patty that’s slightly larger than your bun, place onto a tray and refrigerate for 30 minutes.
While the patties are chilling, bring vinegar, sugar, 1 ½ tsp salt and 200ml water to the boil in a saucepan, remove from heat, and onion and set aside to pickle. Drain before using.
Mix mayonnaise, cumin and lemon juice in a bowl to combine and season to taste.
Heat oil in a large frying pan over medium heat, add lamb patties in batches and fry, turning occasionally until browned and still a little pink in the centre (5-6 minutes), set aside to rest for a minute.
To serve, toast cut – sides of buns and spread bases with cumin mayonnaise. Top each with a patty, feta, pickled onion to taste and lettuce. Sandwich with tops and serve.
Tips
If the lamb mince begins to stick to your hands while forming the patties, try wetting your hands with a small amount of water.
Try using lamb leg steaks, or lamb backstrap (eye of loin) as an alternative to mince.
