Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper.
Heat the avocado oil in a medium skillet over medium-high heat.
Add the diced yellow onion and red bell pepper, sautéing for 3-4 minutes until the vegetables begin to soften.
Add the ground beef to the skillet, breaking it up with a spatula, and cook until browned and no longer pink.
Stir in the chili powder, cumin, garlic powder, sea salt, and black pepper to evenly coat the meat.
Add the tomato paste and water, stirring well to create a light sauce, and simmer for 2 minutes until thickened.
Place the whole wheat tortilla on the prepared baking sheet and bake for 2 minutes per side to slightly crisp it up.
Spread the beef and vegetable mixture evenly over the center of the tortilla, leaving a small border around the edge.
Sprinkle the shredded cheddar cheese over the beef mixture.
Bake for 5-7 minutes, or until the cheese is melted and bubbly and the tortilla edges are golden brown.
Remove from the oven, let cool for 2 minutes, and slice into wedges before serving.