Gather your steaks (I'd suggest 24 – 30 hours prior to the cook). Trim any fat.
Place the steaks in a sealed bag with the marinade (see notes for recipe). If you don't have a lot of time to let these marinade, I'd suggest you consider injecting them to ensure the teriyaki flavor is absorbed into the meat.
About 20-30 minutes before cooking, remove the meat from the marinade and let them come up to room temp after patting them dry with paper towel. This would be the time to set your oven for 500 degrees. You certainly can do these over a grill too and that is typically my preference.
This is a great time to start reducing the remaining marinade into a glaze. Place it in a large sauce pan over the lowest heat setting. Stir occasionally over the next 30 minutes or so.
Remove from heat once the glaze has reached your desired viscosity.
When you're ready to start cooking the steaks, put a cast iron pan over the hottest flame your stove has and let it get piping hot. Then place the steaks onto the pan…. 30 seconds or so should be plenty. This teriyaki marinade will burn due to the sugar, so keep a close eye on it.
Flip and sear the other side.
After searing, place into the oven on a cooking sheet.
Remove the meat from the oven / grill a few degrees below your desired doneness (remember internal temp always will rise a bit after pulling). Let rest at least 5 minutes, if not 10.
Plate your steaks, pour the glaze over the top, and thinly shave the truffle. Enjoy!