The key to reheating lasagna in the Microwave is to start with short intervals. Begin with 20-30 seconds and check on it - if it's not hot enough, give it another 10-15 seconds. Remember, it's better to err on the side of caution to avoid overcooking.
Think of reheating lasagna like baking a cake - you need to keep an eye on it to make sure it doesn't overcook. But, unlike baking a cake, you don't need to worry about precise temperatures or timings. Just use your common sense and adjust the time based on the size of your lasagna portion.
