1. Prepare the Lamb Marinade:

In a small bowl, combine the minced garlic, rosemary, thyme, olive oil, lemon zest, salt, and black pepper.

Rub the mixture all over the leg of American lamb, ensuring it’s well coated on both sides. Cover and let it marinate at room temperature for 1 hour, or refrigerate for up to 4 hours (bring to room temperature before roasting if refrigerated).

2. Make the Pistachio Pesto:

While the lamb is marinating, prepare the pistachio pesto.

In a food processor, combine the pistachios, basil, parsley, garlic, Parmesan, lemon zest and juice.

Pulse until finely chopped.

With the processor running, slowly stream in the olive oil until the mixture is smooth and creamy. Adjust the consistency with more olive oil if needed.

Season with salt and black pepper to taste. Set aside.

3. Prepare the Cranberry Ciabatta Stuffing:

Preheat the oven to 350°F.

Spread the ciabatta cubes on a baking sheet and toast them in the oven for 10-12 minutes until lightly golden. Set aside.

In a large skillet, heat 2 tablespoons olive oil and 2 tablespoons butter over medium heat.

Add the onion, celery, and garlic, and sauté for 5-7 minutes until softened.

Stir in the fresh sage and thyme, cooking for another minute.

Add the dried cranberries and toasted ciabatta cubes to the skillet.

Slowly pour in the chicken stock, stirring to combine. The bread should absorb the liquid but not be overly soggy.

Fold in ½ of the pistachio pesto.

Season with salt and pepper to taste.

4. Stuff the Lamb

Preheat your oven to 425°F (220°C).

Cut 5 long pieces of kitchen twine and lay on cutting board at 1 inch intervals.  

Set the trimmed, marinated, butterflied leg of lamb on top of the twine.

Spread the prepared stuffing evenly over one 1/2 the surface of the lamb. Carefully fold the lamb back up, securing it with kitchen twine in 4-5 places.  Tuck any stuffing that spills out back into the meat.  

Any leftover stuffing you can bake alongside the lamb in a baking dish.

5. Roast the Lamb:

Place the stuffed leg of lamb in a roasting pan.

Roast in the preheated oven for about 80-90 minutes or until the internal temperature reaches 145°F (63°C) for medium rare, 160°F (71°C) for medium, or 170°F (77°C) for well done.

Roast the additional stuffing in the oven for the last 30 minutes of the lamb roasting.

Remove to a cutting board and allow to rest at least 20 minutes before carving.

6. Serve:

Thin the pistachio pesto out with water to desired consistency.  Spread on the base of a large platter.  

Slice the rested leg of lamb and arrange it on top of the sauce.  Garnish with fresh herbs.