Diced beef is not a stir-fry cube unless the pack says it is a minute-steak strip. Extra lean diced beef is a stew: brown it, add liquid, wait. Extra Lean Diced Beef 400g is a 400g pack, a pot for two to three. Braising steaks and chuck in the same shop are the bigger versions of the same idea. Start in diced beef and stewing beef.
Oven stew
Dry the cubes, salt, brown in batches in a casserole so they actually colour — 3 to 4 minutes. If you crowd 400g in a small pan you get grey beef and a boiled taste. Onion, carrot, a spoon of tomato puree, stock to cover. Lid on, 160°C for 2 hours, until a cube yields. Rest 10 minutes. Extra lean mince it is not; extra lean diced still needs that collagen time. If it is still tight at 2 hours, it needs more time, not more heat. Braising Steaks 5x 100g can go in the same pot if you want slices as well as cubes; they take the same 2 hours.
Slow cooker and pie
Brown, then low 6 to 7 hours. For a pie, cool, check the gravy, pastry on top, 200°C for 25 to 30 minutes. Beef Chuck 1.5kg is the joint to shred into a stew if 400g looks mean for the table. Shop slow cooker meat when the week is all pots, and braising steak if you would rather slices than cubes.
What diced beef is not
It is not rump strips for a 6-minute stroganoff unless you bought strips. Extra lean diced in a hot dry wok is how people decide they “cannot cook beef”. Liquid, lid, time. A 400g pack plus potatoes and a vegetable is two dinners or a pie for three. Leftovers freeze in the gravy. Do not add raw cubes to a slow cooker without browning if you care about flavour; you can skip it if you only care about convenience, and the stew will still go tender, just paler.
A 400g pack of extra lean diced beef is two or three plates with potatoes, not a banquet. If you are feeding six, buy two packs or a 1.5kg chuck and cube it yourself. Stew is cheap per plate only when the pot is actually full. Watery cubes in a huge casserole dry on the edges and never go tender together.
Brown in batches, lid on, 2 hours, until a cube yields. That is diced beef stew, and it is a different craft to a frying steak even though both say beef on the pack.