Recipe created by Cravings of a Lunatic
If you substitute the beef for tougher cuts you can marinate longer. Flank, skirt, sirloin and round can marinate for longer, up to 24 hours. Striploin needs very little marinating so I only marinated mine for a short time. It's okay to swap the meat, just adjust accordingly.
If you don't want to take the time to caramelize the onions that's okay. This works well with cooked or raw onions. If you don't caramelize the onions it will cut your cooking time down dramatically.