Deli roast beef is a quick and convenient lunch or snack, but fatal outbreaks of listeria in Canada in 2010 have prompted concerns about the safety of sliced deli meats. Listeria is a bacteria commonly found in vegetables, but it can manifest in deli meats if contamination occurs between cooking and packaging. Approximately 1,700 people become affected by listeria annually, according to the Centers for Disease Control and Prevention, resulting in an average of 260 deaths. The best way to avoid listeria is to heat deli meats to 160 F and use them within three days of buying them.
Preheat your oven to 400 F.
Lay a sheet of aluminum foil flat on the counter. Place your deli roast beef in the center of the foil and fold up all four sides to completely enclose the beef.
Bake the roast beef for 10 to 15 minutes.
Open the foil and fold the roast beef in half to make a thicker layer. Poke the probe of an instant-read thermometer into the beef. The roast beef is safe to eat when the thermometer reads 160 F.
Spray the bottom of a skillet with nonstick cooking spray. Heat the skillet on medium-high for a few seconds.
Place your deli roast beef in the hot skillet and put the cover on.
Cook the roast beef for 2 to 4 minutes and then check the temperature by folding the beef and inserting the tip of an instant-read thermometer into it. Cook the beef until the thermometer reads 160 F.
Place deli roast beef on a microwave-safe plate. Cover the beef with waxed paper or a paper towel.
Heat the roast beef for 3 to 4 minutes at half power. This will help keep it from drying out.
Heat the roast beef for another 30 seconds on high and then check to make sure that it has reached 160 F.