Buttermilk-marinated lamb

To make the monkeygland sauce, heat the oil in a pan over a medium heat and fry the onion and garlic until translucent.
Add the tomato paste and tomatoes and bring to a simmer.
Add the remaining ingredients and simmer for a further 30 minutes or until thick, then remove from the heat and set aside.
To make the onion rings, heat the oil in a large saucepan over a medium heat. Mix the flour, buttermilk, egg, bicarbonate of soda and salt to make a batter.
Dip each onion ring into the batter, shaking off any excess, then fry until golden brown. Drain on kitchen paper and season with salt.
To make the burgers, preheat the oven to 180°C.
Heat the oil or duck fat in a cast-iron pan over a medium to high heat and mix the steak, onion and seasoning.
Shape the mixture into 4 patties and cook for 5 minutes on each side until golden brown.
Divide the cheese between the burgers, then cook in the oven for 5 minutes, or until cooked to your liking.
Spread the bottom half of each roll with mayonnaise, then top with lettuce and monkeygland sauce.
Top with the cooked patties, onion rings and top halves of the rolls.