Prep: Preheat oven to 350 degrees F. Spray a small baking dish non-stick cooking spray, set aside.
Prepare Jack-O-Lanterns: Take bell peppers, one at a time. Lay flat on its side on a cutting board and cut off the top of the pepper as thin as you can (do not discard). Use a small paring knife to scrape/cut out the seeds and membranes from the inside of the pepper. Then use the same paring knife to carefully cut a jack-o-lantern face into the front of the pepper, just like you would on a pumpkin. Repeat with all peppers and set in the prepared baking dish.
Bake: Bake the bell peppers (with tops) for approximately 15-20 minutes or until your desired softness.
Cook Filling: Meanwhile, take a large cast iron skillet and bring to medium-high heat. Add olive oil and swirl to coat the pan. Add 2 teaspoons garlic and let cook until fragrant, about 30 seconds. Add onion and cook until it reduces, about 2-3 minutes. Add ground turkey to brown in the hot pan. Break apart and allow to cook, about 5-7 minutes, or until fully cooked. Add taco seasoning, 1 tablespoon water, 1 tablespoon tomato paste, and diced tomatoes; stir to combine. Taste and adjust seasoning, if desired.
Stuff Peppers + Cheese: Scoop taco mixture into each pepper. Add about 1/4 cup of shredded cheese on top of each one. Return to the oven to bake until cheese is melted.
Serve: Enjoy immediately with your desired toppings.
Notes
Whole30/Paleo Version: simply omit the cheese on top.
Black Beans + Rice (Vegetarian) Version: Prepare the peppers the same way, but stuff them with some homemade black beans and rice or use a boxed black beans & rice. Stuff each pepper with some black beans & rice, add cheese on top, and serve with your favorite toppings.
Ground Turkey: option to use ground beef or ground chicken, if you prefer!
Tomato Paste: I like to use a tube of tomato paste, so I don't have to open a can only to use one tablespoon.