Marinate the beef in Natrel Lactose Free for 4 to 8 hours or overnight. Discard marinade, tie up with string so the meat will keep its shape, cover with plastic wrap and refrigerate until ready to cook.

Preheat the oven to 300°F. Bring the beef to room temperature, coat in 1 tbsp olive oil and rub in ½ tsp salt and pepper, then sear in a skillet over medium-high heat for 3 to 4 minutes each side.

On a piece of parchment paper, combine breadcrumbs and spices. Coat the beef with a little more olive oil and roll in the breadcrumb mixture until evenly coated.

Place in a small roasting pan and cook for 1 hour and 25 minutes for medium-rare, or insert a thermometer and cook until desired doneness.

Meanwhile, bring a pot of salted water to a boil and add potatoes; boil for 10 to 15 minutes or until a knife can be inserted easily into the potatoes.

Drain in a colander and transfer the potatoes back to the saucepan; cover with the lid and give the pan a good shake to fluff the potatoes. Transfer to a roasting pan and coat with oil, salt, rosemary and garlic, and bake alongside the roast for 50 minutes to 1 hour until the potatoes are crispy and golden brown. Turn potatoes halfway through to ensure even browning.

In a bowl, mix together onion, mushrooms, garlic and olive oil. At the halfway point, combine the mixture with the beef, and roast together until the beef is done.

Transfer the beef to a cutting board, cover with foil and let rest for 10 to 15 minutes. In a saucepan, add the roasted onions and mushrooms.

Deglaze the roasting pan with the stock and balsamic vinegar then transfer the liquid to the saucepan with the onions and mushrooms.

Add the flour and Natrel Lactose Free, and bring to a simmer for 5 to 10 minutes until thickened. Season with salt and pepper. I prefer this gravy on the chunky side, but if that’s not to your liking, feel free to smooth it out in a blender.

Add any remaining juices from the resting meat to the gravy then slice the beef and serve.