Yes you can reheat shepherds pie in the microwave but watch the pie closely and microwave it for a few minutes at a time and check on it between those minutes.
It usually takes 5 to 7 minutes to reheat shepherds pie in the microwave but it can vary from microwave to microwave depending on the power of the microwave.
Although you can reheat shepherds pie in the microwave the best way to reheat shepherds pie is in the oven for 10 to 20 minutes or until it's reheated.
The microwave can easily burn the shepherds pie if you're not careful but the oven heats the shepherds pie up much more evenly.
Just preheat the oven to 350 and place the shepherds pie in the oven for 10 to 20 minutes or until the shepherds pie is warm enough and heated up enough for you.