Steak for two fails when one steak sits while you fuss the second, or when you buy a 10-pack because it looked cheaper and then cook two badly. A 2x pack is the right shop. Steak for two is built from those packs: sirloin, rump, ribeye and fillet in pairs.
One pan, two steaks
Get a pan wider than both steaks. If they overlap, you are steaming. Sirloin Steak 2x 8oz wants 2 minutes 30 seconds a side for medium-rare, rest 5 minutes. Rump Steak 2x 6oz wants about 2 minutes a side and a strict slice across the grain. Rib-eye Steak 2x 6oz wants the fat edge rendered. Fillet 2x 6oz wants a probe and an early pull at 52°C. Salt both, cook both at the same time, rest both on the same warm plate. That is how two people eat together rather than in shifts.
BBQ and air fryer for two
BBQ: both steaks on the hot zone together, same times as the pan, then rest off the grill. Air fryer: 200°C, both in a single layer, 7 to 9 minutes for 6oz, turning once. Two 8oz sirloins may need a minute more. Do not stack them. A 2x pack is also the right size for a week-night reverse sear: 80°C oven 15 to 20 minutes then 45 seconds a side in the pan, which you can do while you plate a salad.
What not to buy for two
A 10x pack is a freezer fill, not tonight’s supper, unless you will freeze eight steaks the same evening. A 16oz or 20oz sharing steak is a different meal — one piece, sliced between two — and it lives with the big cuts, not in the 2x packs. If you cannot agree on a cut, cook one sirloin 2x and keep a fillet 2x for another night; mixing two cuts in one pan only works if they are the same thickness. Pair the steaks with something from sirloin steaks or fillet steaks and keep the rest of the order for the freezer.
If one of you wants it more done, cook both to medium-rare, rest, then give the second steak 45 seconds more in the pan after you have plated the first. That is kinder than cooking them to different times from the start and serving one cold. Chips, a salad, or a few mushrooms in the steak pan after the meat rests is enough of a side.
Same pan, same time, same rest. Two steaks, two plates, one sitting. That is the point of a 2x pack.