Preheat the oven to 350 degrees and lightly grease a loaf pan.
In a large bowl, combine the ground beef, flaxseed meal, drained green chiles, egg, onion, garlic, chili powder, cumin, salt, and black pepper.
Mix with your hands until the ingredients are evenly distributed, then fold in the shredded pepper jack cheese.
Transfer the mixture to the prepared loaf pan and press it down evenly.
Bake for 50 to 55 minutes until the internal temperature reaches 160 degrees.
Remove from the oven and let the meatloaf rest in the pan for 10 minutes before slicing.