In a 10-inch oven-proof skillet set over medium heat, brown ground beef until mostly cooked through, breaking up any clumps with the back of a wooden spoon. Stir in the the taco seasoning and chili powder.
In a small bowl, whisk the tomato paste with the water until well combined. Pour over the beef and stir in, then remove from heat. Sprinkle with shredded cheese.
In a large bowl, whisk the coconut flour, almond flour, sweetener, baking powder, xanthan gum, and salt. Stir in the eggs, butter, green onion and almond milk until well combined. Your batter will be quite thick.
Dollop the batter over the beef in the pan. Use a knife or an offset spatula to spread over the top and to the edges.
Bake 40 to 45 minutes, or until the edges are golden brown and the top is firm to the touch. Remove and let cool 10 minutes before serving.