Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup.
In a mixing bowl, combine ground beef (or turkey), almond flour, shredded cheddar cheese, egg, taco seasoning, garlic powder, salt, and pepper. Mix until well combined.
Gently fold in the diced green peppers and chopped onion.
Use your hands to form the mixture into meatballs, about 1.5 inches in diameter, and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for about 20-25 minutes, or until they are cooked through and browned on the outside.
While the meatballs are baking, heat the enchilada sauce in a large skillet over medium heat.
Once the meatballs are done, transfer them to the skillet and coat them in the heated enchilada sauce. Cook for an additional 2-3 minutes.
Serve the meatballs topped with fresh cilantro if desired.