Lamb tenderloin with a basil stuffing in a salt crust

Ingredients

• 2 boneless single top loins with tenderloins attached if possible, trimmed of all fat,12 to 14 ounces each (340 – 400 g)
• 3 ounces (80 g) fresh bread crumbs
• 1 ounces (leaves from about 4 stems) flat leaf parsley
• 3-4 ounces (2 good bunches or about 3 loosely packed cups) basil leaves
• 1 teaspoon fresh thyme leaves
• 6 tablespoons (80 g) soft butter
• 1 clove garlic
• Pinch of salt
• Freshly ground pepper
• 2 tablespoons olive oil
• For the salt crust
• 1 cup (220 g) coarse sea salt, sel gris, or kosher salt
• 1 teaspoon rosemary
• 1 teaspoon thyme
• 1/3 cup (80 g) water
• 2 cups (240 g) flour
• 1 egg
• 1 egg yolk
• Egg wash (1 egg yolk mixed with 2 tablespoons of water)

Instructions

1. Preheat the oven to 420 °F (220 °C). Line a roasting tray with parchment paper.
2. To make the salt crust, mix the flour, salt, rosemary and thyme in a large bowl. Add the egg and egg yolk and half the water, holding back in case it is not needed. Knead the mixture with your hands until it forms a dough. Shape the dough into a ball, then wrap in plastic film and set aside at room temperature until needed.
3. To make the herb filling. Place the fresh herbs, thyme, butter, bread crumbs, garlic and a pinch of salt in the bowl of a food processor and pulse until the mixture forms a smooth paste. Set aside.
4. Place the lamb loins on a cutting board so that the former skin side is down. If working with a loin with the tenderloin attached, push the smaller tenderloin aside and spread half the basil, breadcrumb mixture over the length of the larger loin. Place the tenderloin on top to make a sandwich and repeat with the second loin.
5. If you are cooking a top loin without the tenderloin to sandwich the filling, use a paring knife to cut a 3-inch wide pocket, about 2-inches deep, into the side of each loin. Fill the cavity with the basil mixture.
6. Using kitchen twine, tie the tenderloin at each end and in the middle to secure the filling. Season the stuffed loins with pepper.
7. Heat the oil in a heavy-bottomed sauté pan and swirl to coat. Add the lamb former skin side down and cook to sear, about 1 minute. Turn and sear the other side. Remove and set aside to cool.
8. Place half the salt dough on a large piece of parchement paper on a work surface. Roll out the dough until ¼ inch (5 mm thick). Place the lamb, former skin side down in the centre of the dough, and bring up the sides to completely enclose the lamb and pinch together to seal. Patch any holes with excess dough. Roll it over and place it on the prepared roasting pan, seam side down. Brush well with the beaten egg and repeat with the 2nd loin.
9. Roast the lamb for 20 minutes, remove from the oven and leave the lamb to rest for 5 minutes; the lamb will be medium–rare. (Or continue to roast until cooked to your liking.)
10. To serve, cut the top off the crust (like removing the lid from a chest), remove the lamb, slice and serve with any juice that accumulated in the crust. Delicious accompanied by roast potatoes and a green salad.