Dice the onion and mince the garlic. In a skillet and with medium heat, sauté the onion and garlic in a neutral oil such as avocado or grapeseed oil. Preheat oven to 350 Fahrenheit (176 Celsius).
Add the ground turkey to the skillet with a pinch of salt and some freshly cracked pepper. Make sure to really break down the turkey meat with your spatula as it likes to clump together under heat.While the turkey is cooking, grab a dutch oven or saucepan and bring water about 1/4 of the way to a low boil.
With a knife, cut off 1/8 of the bell peppers at the very top to allow the centers and seeds to be removed and flatten the bottoms. Repeat until all bell peppers have flat tops, empty cavities, and can easily stand up on their own.
Place prepared bell peppers in the shallow pan of water, and boil for roughly 5 minutes so the skins can soften up a bit. Remove from pan once finished.Once the turkey is evenly browned, turn down the heat and add the cooked rice and stir with a spoon or spatula until thoroughly combined.
Add the tomato sauce and some more salt and pepper and bring to a simmer. Turn heat off. Grab an 8-inch square glass baking dish and stand the bell peppers upright inside dish. With a spoon, fill each bell pepper all the way up to the top with the cooked turkey and rice mixture.
Once all peppers have been filled, top each stuffed bell pepper with shredded mozzarella cheese. Cover with aluminium foil and place in the oven.
Bake for 10 minutes. Remove foil and cook for an addition 15 minutes until cheese has browned. Garnish with fresh parsley or cilantro if you would like!