Thinly slice the flank steak against the grain into bite-sized strips.
In a small bowl, whisk together the chili powder, smoked paprika, sea salt, black pepper, and lime juice to create a marinade.
Toss the steak strips in the marinade until evenly coated and let sit for 5 minutes.
Heat the avocado oil in a large non-stick skillet over medium-high heat.
Add the sliced red bell peppers and onions to the skillet, sautéing for 3-4 minutes until they are tender and slightly charred.
Add the steak strips to the skillet and sear for 2-3 minutes until browned and cooked to your desired doneness, then remove everything from the pan.
Wipe the skillet clean and place the almond flour tortilla in the center over medium heat.
Sprinkle the shredded cheddar cheese over one half of the tortilla.
Layer the steak and vegetable mixture over the cheese and fold the tortilla in half.
Cook for 1-2 minutes per side until the tortilla is golden brown and the cheese is completely melted.