When you want to reheat steak that you originally cooked on your grill there is a few things you need to consider. You don't want to cook the steak using a method that will dry it out. In addition to this, you want to make sure you heat it to a temperature that is safe for consumption. Reheating your steak in a sealed plastic bag, in a pot of boiling water is one way to do this.
Fill a large pot about half the way full with water. Bring the water to a boil.
Thaw steak if it is frozen. Otherwise, take it out of the refrigerator and allow it to reach room temperature.
Place your grilled steak in a food storage bag with a zip seal. Add 1/2 tbsp. of butter and any desired seasonings. Seal the plastic bag.
Submerge the bag into the pot of boiling water with metal tongs. Reduce the heat to medium. Allow the steak to cook for about 5 to 10 minutes.
Remove the bag from the pot with metal tongs. Insert a meat thermometer into the center of your steak at its thicket point. The internal temperature of the steak should be 165 degrees Fahrenheit or higher.