Batch 1: soaked for too long in vinegar.
Batch 2:
• 3 hours soaking was too little - need maybe between 4-6 hours.
• Meat was thicker this time - put fan on medium if thicker to reduce the outside getting too hard too quick.
• London broil was fattier - top round from market was better cut.
• Chilli sticks were great - cut them 1cm x 1cm next time.
1lb is a good amount for the box