- for the lamb:
- 1 large baking potato (peeled, about 375g)
- 5 tsp olive oil
- 2 tsp chopped flat-leaf parsley
- 2 tblsp dried white breadcrumbs
- 2 (450g each) boneless loins of lamb (completely trimmed of fat)
- salt and freshly ground black pepper
- sprigs of mint, to garnish
- for the tarragon jus:
- 50 ml balsamic vinegar
- 200 ml maderia sauce
- 1 tsp tomato purée
- 1 tsp light muscovado sugar
- 1 tblsp chopped tarragon leaves
- for the pea and mint purée
- 4 tblsp double cream
- 1 tblsp chopped mint
- 225 g fresh or frozen peas
- 1 tblsp butter (at room temperature)
- 2 tblsp milk
- Preheat the oven to 200°C (400°F/Gas 6). Cut the potato into long, thin strips (julienne) using either a mandolin, the coleslaw blade of your food processor, or by hand. Pile the strips into the centre of a clean tea towel and squeeze out all of the excess water.
- Heat 2 teaspoons of olive oil in an 18cm (7in) frying pan over a high heat. Reduce the heat a little, sprinkle over half the potato strips in a thin, even layer, and press down the crust as it cooks for about 3-4 minutes until crisp and golden on the bottom, leaving the top of the potato crust uncooked. Slide out of the saucepan crispy-side down, on to a clean tea towel. Repeat with another 2 teaspoons of oil and remaining potato. Sprinkle the uncooked side of the potato crusts with the parsley.
- Place the dried breadcrumbs on a flat plate. Season the trimmed lamb loins well with salt and pepper then roll each piece in the dried breadcrumbs to evenly coat it all over. Place one loin at the edge of the potato crust. Roll up like a Swiss roll, using the tea towel to lift it up and over, while squeezing the potato tightly around the lamb, so that it sticks to it and completely encloses it.
- Use the remaining teaspoon of olive oil to grease a wire rack set in a roasting tin. Transfer the lamb onto the rack, seam-side down (the potato crust stays more crisp that way). Bake for 20-25 minutes for medium or longer is you prefer your meat well-done.
- Meanwhile, to make the tarragon jus, heat a medium-sized saucepan until quite hot. Add the balsamic vinegar, and as soon as it stops bubbling, add the Maderia Sauce, tomato purée, sugar and tarragon and boil for about 5 minutes until it is reduced by three-quarters and well flavoured. Season with salt and pepper and keep warm over a low heat.
- To make the pea purée, place the cram and milk in a medium-sized saucepan with the mint and bring to the boil. Add the peas and butter and cook for 2 minutes (or 4 minutes if the peas are frozen). Season the pea mixture with salt and pepper to taste and then transfer to the food processor. Whiz until well blended to a smooth purée, then pass through a sieve into a clean saucepan and reheat gently. Keep warm over a low heat.
- Remove the lamb from the oven and allow to rest, uncovered, on kitchen paper for 5 minutes. Then cut each piece of lamb into four thick slices. Arrange two pieces of lamb on each warmed plate and garnish with fresh mint. Serve with a spoonful of the pea purée alongside a drizzle of the tarragon jus.
Neven's notes: I've got Lea Linster to thank for this dish. Don't be worried by how small the lamb loins appear after being trimmed down- each piece might end up weighing no more than 200g (7oz). The best way to make dried white breadcrumbs for the crust is to toast some bread and simply blitz it in a food processor.