A Sunday roast fails on the rest, not the oven. People carve the minute the joint looks done and then wonder why it is dry. Pick one joint that matches the table, give it the right heat, and leave it alone under foil while you finish potatoes. Shop Sunday roast and large roasting joints rather than buying three tiny joints that will all overcook.
Beef, pork or lamb
Topside Joint 1kg is a small beef roast: brown, 180°C, probe 52–54°C for pink, rest 20 minutes, slice thin. Pork Loin Joint 1kg wants 70°C and a hotter start if you care about the fat cap. Whole Carvery Leg of Lamb 2.2-2.7kg is a 2.2–2.7kg bone-in leg, 180°C, about 20 minutes per 500g plus 20 for pink, rest 25 minutes. Do not cook all three. One joint, done properly, beats a crowded oven of mixed meats that all come out wrong. Sirloin joint is the nicer beef if you want steak-like slices; topside is the leaner, cheaper one.
Timing the rest of the plate
Potatoes in the hottest oven once the joint is resting — or start them first if your oven will not recover. Gravy from the tin: onion, flour, stock, a boil. Yorkshire puddings in the beef fat if it is a beef Sunday. Shop beef joints or pork joints when you know the species before you know the cut. A 1kg joint is four people; a 2kg-plus joint is a do. Match the weight to the table so you are not reheating a dried leftover mountain on Monday unless you like cold cuts — in which case a 3kg pork loin is a feature, not a mistake.
What a Sunday is not
It is not a tray of sausages. It is not a 6oz steak. Those are week nights. It is also not a 90°C 12-hour brisket unless that is the Sunday you wanted; brisket is a pot roast and it lives on a different page. Probe, rest, carve across the grain, serve hot plates. Leftover roast, cold and pink in the middle, is the test of whether you roasted it right. Grey leftover beef is a joint that went too far before it even hit the table.
If two joints must go in, pick two that want the same 180°C, not a pink beef and a 150°C shoulder. A topside and a pork loin can share an oven; a brisket and a fillet cannot. That matching of joints is the real Sunday skill, and it is why the Sunday roast collection exists as a shelf rather than as a dare to cook the whole shop at once.
One joint, the right temperature, a long rest, gravy from the tin. That is a Sunday roast from Meatsupermarket.com, and it is still the best reason to turn the oven on for the afternoon.