Thinly slice the flank steak against the grain into bite-sized strips and season evenly with the ground cumin, chili powder, sea salt, and black pepper.
Seed and dice the poblano pepper and finely chop the red onion.
Heat the extra virgin olive oil in a large cast-iron 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 through, then transfer to a plate and set aside.
In the same skillet, add the diced poblano peppers and red onions, sautéing for 4-5 minutes until they are tender and show slight char marks.
Wipe the skillet clean with a paper towel and place the whole wheat tortilla in the pan over medium heat.
Sprinkle half of the Monterey Jack cheese over one half of the tortilla.
Layer the cooked steak, sautéed peppers, and onions over the cheese, then top with the remaining cheese.
Fold the tortilla in half and cook for 2 minutes per side until the exterior is golden brown and the cheese is fully melted.
Remove from the heat, let it rest for one minute, then slice into three wedges and serve.