I cut it up into 1.5 inch cubes and cooked it at 200 degrees F. I'm trying to make brisket curry and It's just been simmering at that temp for the last 3-4 hours. It's still super hard. Did I ruin it already?
Brisket takes a long time as it's so tough to begin with, just keep cooking it. It may take another 2 or more hours to get tender. Just be patient, with brisket you have to cook for a result not a time.