How to make nadan beef roast soft and juicy?

I have had beef roast from different parts of Kerala, and they are usually soft, but when we try to make it at home, it is usually ends up quite hard☹️We first pressure cook it and then roast it for about 30-40 minutes. What is it that we are doing wrong? Share your recipes please!

P.S Please give detailed instructions about the cooking part. I’m a noob in cooking, I religiously follow Shan Geo for cooking videos because he tells how much salt to put. I’d be totally lost otherwise. 🥲