I'd start with one minute but check it after 30 seconds & continue to check. I've microwaved grilled stuffed steak burritos and hard tacos and I gotta be honest. They don't re-heat too well. I actually had better luck re-heating my burrito in the oven after wrapping it in aluminum foil but I had time to wait for it to cook. If you have a toaster oven it would heat better.