Thinly slice the top sirloin steak into bite-sized strips and season evenly with sea salt, black pepper, garlic powder, and ground cumin.
Heat the avocado oil in a large cast-iron or stainless steel skillet over medium-high heat until shimmering.
Add the steak strips to the skillet in a single layer and sear for 2-3 minutes until browned and cooked to your preference, then remove from the pan and set aside.
In the same skillet, add the sliced bell peppers and red onions, sautéing for 4-5 minutes until the vegetables are tender and exhibit a slight char.
Wipe the skillet clean and return it to medium heat, then place the sprouted grain tortilla in the center.
Sprinkle half of the shredded Monterey Jack cheese over one half of the tortilla, then layer on the seared steak and sautéed vegetables.
Top the filling with the remaining cheese and fold the tortilla over to close.
Press down lightly with a spatula and cook for 2 minutes per side until the tortilla is golden brown and the cheese is fully melted.
Transfer to a cutting board, let rest for one minute, then slice into wedges and serve.