Slice the tops off of the peppers. Reserve the tops to dice and use in the meat mixture later. Clean out the seeds and ribs inside of the peppers and place them in a baking dish. Add about 1 cup of water to the bottom of the dish, and cover with foil. Place dish in the oven and preheat to 400º. This will give the peppers a head start to begin steaming while you make the filling.
While the oven is heating and the peppers are steaming, prepare the veggies. Chop the pepper "tops" into small cubes, dice the onions, and slice the mushrooms.
Heat a large skillet over medium heat. Add 1 Tbsp oil and saute the onion and bell peppers until soft (about 5 minutes).
Add the ground beef and begin to break it up and mix it into the peppers/onions. Add salt, pepper, and garlic powder. Once the meat is just about browned, add the mushrooms and mix them in. Finally, add the coconut aminos and stir one last time!
Remove the peppers from the oven and carefully uncover. Using a spoon, evenly fill the peppers with the meat mixture to the brim. Fill until the mixture is used up.
Re-cover the peppers with foil, and place back into the oven for 20 minutes. Remove from oven and take off foil. Add cheese slices (I didn't need a full slice for each one). Place back into the oven and cook uncovered for another 8 minutes.
Allow to cool, and serve with a nice little side salad! Enjoy!
