Preheat the pellet grill smoker to 225°F (107°C) and activate the Super Smoke setting if available.

Finely mince 4 tablespoons fresh rosemary and 3 garlic cloves; zest 1 lemon with the microplane grater.

Mix 2 tablespoons fresh rosemary, garlic, smoked paprika, lemon zest, olive oil, 1 teaspoon sea salt, and cracked black pepper in a small bowl.

Coat all 4 lamb shanks completely with the rosemary and paprika rub.

Place the seasoned lamb shanks directly on the grill grates and smoke for 240 min.

Spritz the lamb shanks with apple juice every 60 min while they smoke.

Continue smoking the lamb for up to 60 min more, until golden, very tender, and pulling easily from the bone.

Peel and cube 4 lb potatoes into evenly sized pieces.

Cover the potato cubes with salted water in a large pot and simmer until nearly fork-tender, about 12 min.

Drain the par-cooked potatoes and spread them on the sheet pan.

Put 200 g duck fat on the sheet pan and place it on the grill until the fat melts, about 5 min.

Add the potatoes, remaining 2 tablespoons rosemary, and 1 teaspoon sea salt to the hot duck fat; gently toss to coat.

Grill the potatoes for 45 min, turning them halfway through, until deeply golden and crisp.

Slice the English cucumber thinly into rounds.

Boil 1/2 cup water in the electric kettle.

Combine white wine vinegar and sugar in a small bowl, then slowly stir in the boiling water until the sugar is mostly dissolved.

Add the sliced cucumber to the brine and toss until fully coated.

Set the quick pickles aside for at least 20 min while the lamb and potatoes finish cooking.

Arrange the smoked lamb shanks and crispy potatoes on a serving platter.

Serve with quick pickles, tzatziki, feta cheese, fresh mint, lemon wedges, and pita bread.