Preheat the oven: preheat the oven to 180°C / 350-375°F / Gas Mark 4-5.
Baking dish: lightly spray a baking dish with olive oil, then set aside.
Dry rub: add the mustard powder, brown sugar, garlic powder, onion powder, paprika, cayenne pepper, salt and pepper to a small glass and use a mini whisk to stir and combine then set aside.
Rub onto ribs: use tongs to place the lamb ribs onto a clean dry chopping board. Then sprinkle half of the rub across the ribs and use your fingers to massage the rub all over the ribs, rubbing it into the meat as you go. Use tongs to flip the ribs and repeat for the other side, top and bottom.
Worcestershire sauce: pour the sauce into the base of the oiled baking dish.
Oven bake: then use kitchen tongs to place the rub covered ribs into the baking dish. Next cover the dish with tin foil and place the ribs into the preheated oven on the middle shelf. Allow them to cook for 1 hour.
Bake uncovered: after 1 hour use oven mits to remove the baking dish from the oven and discard the aluminium foil. Then place the ribs back into the oven uncovered and bake them for 10 minutes, After 10 minutes, use oven mits to remove the baking dish and place it onto a heatproof surface.
Grill/broil: change the oven setting to grill at 200°C 392°F6.
Baste: use kitchen tongs to transfer the ribs onto a silicon mat over a baking tray with rack. Then use a pastry brush to coat the ribs in the sauce. Once covered, place the baking tray into the oven on the top shelf and grill the ribs for 10 minutes. After 10 minutes use the oven mits to remove the tray and do another layer of sauce, then return the ribs to the oven for a final 10 mins grill time (Total grill time is 2 x 10 mins = 20 mins).
Serve: remove the grilled ribs from the oven and place them onto a heatproof surface. Let them rest for 2-3 minutes before transferring them to a serving plate and provide a bowl of sauce alongside them.