Preheat the oven to 250°F to 300°F
Place the meatloaf in an oven-safe dish
Add a little broth, water, or gravy to keep it moist
Cover the dish tightly with foil
Heat for 20 to 30 minutes, or until warmed through
Check that the internal temperature reaches 165°F
Let it rest for a few minutes before serving
Reheat slices in a skillet over low heat if preferred
Reheat slices in the microwave on medium power in short intervals
Cover slices when microwaving to prevent drying out