First method: dry marinating the meat with sea salt for an hour.
Second method: cooking the meat with low heat using 80 degrees Celsius (electric oven) for 30-40 minutes.
The cut looks like the one on the right:
I used these two methods today (one followed by the other), and my steak was still tough and chewy.
What could be the reason?
Note: It's a sirloin steak.