Rinse of your sweet potatoes and place them in a glass microwave safe dish with about a 1/2 inch of water. Pierce the potatoes a few times, cover and cook in the microwave for 10 - 15 minutes. All microwaves are different so you'll just want to ensure the potatoes are cooked all the way through and are soft.
While the potatoes are cooking take your cast iron skillet and cook the beef, onion, carrots and mushrooms until the beef is no longer pink and the carrots are soft. Mix in the cinnamon, allspice, nutmeg, 1 teaspoon of black pepper and 1 teaspoons of the salt.
Take your sweet potatoes out and give them a minute to cool so they are easy to handle. You'll make a cut down the middle of the potatoes and then scoop out all the good stuff into a mixing bowl.
Mash the sweet potatoes with the egg, butter, coconut milk, 1 teaspoon of black pepper and 1/2 teaspoon of salt. Mash the potatoes until they are smooth.
Spread the mashed sweet potatoes over the ground beef as evenly as possible.
Bake the dish in the oven at 350 degrees for approximately 22 - 25 minutes.
Broil the dish for 8 minutes to give it a nice finish.