Preheat the oven to 200°C and butter four large ramekins.
Simmer sliced potatoes in cream, milk, garlic, and spices for 10 minutes until tender.
Layer potatoes in ramekins, add reserved liquid and Gruyère, then bake for 25 minutes.
Boil lamb trimmings and vegetables in 450ml water for 10 minutes to make stock.
Reduce strained stock by half, add port and jelly, then thicken with arrowroot and redcurrants.
Brown seasoned lamb in oil, then roast at 200°C for 14 minutes and rest.
Blanch broad beans for one minute and remove their outer membranes.
Boil baby leeks for two minutes, adding the beans for the final 30 seconds.
Carve lamb into cutlets and serve with unmoulded potatoes, vegetables, and port sauce.