Fire up your Ooni pizza oven and set it to the lowest gas flame. If using wood/charcoal, aim for a low flame (as close to 250°C in the oven’s centre as possible).

Add the Dual-Sided Grizzler to the oven (smooth side up) and heat for 5 minutes. Carefully remove using the handles. Toss the diced lamb in olive oil with a pinch of salt and pepper, then evenly distribute on the Grizzler and pop it back in the oven for 3 minutes.

Remove the Grizzler and use metal tongs to turn the meat, so it evenly browns. Return it to the oven for 3 minutes. Remove the Grizzler and reserve the lamb to prevent further cooking. Drain the juices into a bowl containing the diced onions, carrots, and celery. Toss to evenly coat and return them to the Grizzler, evenly distributing them.

Return the Grizzler to the oven and cook for 2 minutes. Remove, use tongs to toss the veg, and return to the oven. Repeat twice to ensure the onions turn translucent.

Remove the cooked vegetables to a roasting dish, add the garlic and lamb, and toss thoroughly to combine. Place the roasting dish on a baking tray.

Return the dish (on the tray) to the oven. When the mix sizzles (about 2 minutes), retrieve, add the wine, then return it to the oven. Cook for 3 minutes, then turn the dish 180° and cook for 2 more minutes.

Add the stock and redcurrant jelly, then toss to combine. Top with the large sprig of rosemary and cover the dish with 4 layers of foil, ensuring the sides are crimped and sealed. Return to the tray and replace in the oven for 20 minutes. Rotate 180° and cook for 20 more minutes. Repeat for a full 80 minutes.

Turn off the oven and leave the dish inside for 20 minutes. Remove the filling to a container and let it reach room temperature. Check the seasoning and adjust as necessary.

Lightly grease a pie dish with butter or oil, then layer the bottom with puff pastry to line the base and sides. Layer the filling evenly over the pastry, then cover the pie with the second sheet of puff pastry. Seal the sides with a fork and trim off any excess pastry.

Mix the egg and milk to make an egg wash, then glaze the pastry.

Preheat the oven on the highest flame for 5 minutes to no more than 450°C. Return the pie to the baking tray, turn off the flame, and replace the tray in the oven as close to the back as you can. Leave for 25 minutes to cook in the residual heat, turning 180° halfway through.

Retrieve the pie, then return the oven to a full flame to reheat the stone. Reduce the flame to its lowest setting, cover the pie with foil and return to the mouth of the oven. Cook for 15 minutes, turning every 5 minutes. Remove the foil and let the pastry cook, turning it to ensure it browns evenly.

Remove the pie and use a sturdy spatula to cut into 4 to 6 portions. Enjoy with your favourite sides, such as crispy roast potatoes or maple-glazed carrots!