Hi chefs Home cook here. We had steaks last night with a mustard dressing. Oil, vinegar, mustard, mustard seeds, capers, garlic. It was amazing. Just before serving I noticed the dressing had split. I made it before cooking steak as steaks cook in 3 minutes (thin sirloin). Adding a bit of vinegar and mustard and whisking vigorously brought it back. How do you guys keep emulsified dressing stable?