Ingredients

• Lamb or chicken stock - 300 ml.
• Dry sherry - 50 ml.
• Dry white wine - 100 ml.
• Membrillo - 85 grams. (You need to keep some extra to taste)
• Extra virgin oil - 3 tablespoons.
• Rosemary sprigs (Leaves only) - 4 nos.
• Garlic cloves - 8 nos. (They must be peeled and cut into slivers)
• Leg of lamb - 2 kg.

• #Ingredients for potato gratin#
• Thyme sprigs (Leaves only) - 2 nos.
• Garlic cloves - 2 nos. (Finely sliced)
• Whole milk - 85 ml.
• Sour cream - 140 ml.
• Double cream - 425 ml.
• Celeriac - 500 grams.
• Potatoes - 500 grams.
• Peeled and cooked chestnuts - 100 grams. (You can use vacuum packed 10 gram butter)

Cooking guidelines

Deep incisions must be made all over the lamb.

A sliver of garlic should be stuffed into every incision and it must be followed by a few rosemary leaves.

Olive oil has to be rubbed all over the joint and into the incisions, and you need to place it in a roasting tin with covering loosely using a cling film before placing in the fridge for a few hours to marinate.

The lamb should be brought to room temperature and the oven needs to be heated to 390 Degree Fahrenheit.

Half portion of the membrillo should be spread on the underside of the joint and seasoned with pepper and salt.

It has to be set into a roasting tin and the remaining part of the membrillo has to be spread by pushing into the incisions as well before seasoning and roasting for 30 minutes.

For making the gratin, celeriac and potato must be peeled and sliced finely.

The milk and creams have to mixed together in a saucepan and brought to boil.

Thyme, garlic and sliced vegetables should be added and cooked for 5 minutes.

The chestnuts have to be sliced and you need to season the vegetables really well before placing half into a gratin dish that is buttered. (Spread them in an even manner)

The chestnuts and vegetables must be spooned on top and the oven has to be turned down to 30 Degree Fahrenheit.

The lamb has to be roasted for 60 minutes, and the wine and sherry must be added within 45 minutes of roasting. (Make sure that you are pouring them round the joint)

15 minutes after reducing the heat of the oven, gratin has to be added.

After cooking the lamb, it should be placed in a warm platter and some foil should be used to cover and towel must be used to insulate before setting aside for 15 minutes.

The roasting tin has to be put over medium heat and stock should be added before bringing to the boil. (You can boil until the preferred taste is achieved)

The sauce has to be strained through a sieve before serving with the lamb.