I've seen this, but it does not answer my question.
The steak pieces: 1kg bought from a local beef shop where they just take a random piece of meat, chop it into little pieces of around 2 or 3 cm in size and give it to you.
What I did: Kept it in freezer for two days, took it out today and put it in water and heated the water a little. Pulled apart frozen pieces slowly in a span of an hour and allowed it to reach room temperature.
Recipe: Added spices as per this recipe and left for marination for an hour.
Pressure cooker: Put beef in cooker and heated on slow fire for 35min until there were 4 whistles/steam-let-outs that happened in a span of 2 minutes. Allowed pressure to go down and after around 20 min, opened the cooker to find the meat very rubbery. Appeared slightly cooked on the outer layer for 1 or 2 mm, but the meat inside seemed raw and when I try to tear it, it feels tough and rubbery and extends a little like when you start pulling chewing gum apart with both hands.
Beef meat ends up like this every single time I try to cook it in a pressure cooker. I'm sure I didn't overheat it and it certainly wasn't cooked for too long. Or is it wrong to cook it in a pressure cooker and instead boil it in an open top container? I hadn't added vinegar or wine or lemon juice during marination. Could they have made a difference?
ps: I continued heating the beef with its gravy for another 20 min on low flame, but it didn't seem to make the meat any better. So I separated the gravy and roasted it as in this recipe. The taste turned out excellent but the meat was still rubbery. So it would be much appreciated if you could help with info on ensuring that the meat is tender and well cooked when we start cooking it itself.