Slice the flank steak into very thin strips against the grain to ensure maximum tenderness.
In a small bowl, whisk together the chili powder, smoked paprika, sea salt, and black pepper.
Toss the steak strips with the spice blend and the lime juice until every piece is evenly coated.
Heat half of the olive oil in a large skillet over medium-high heat and sauté the sliced peppers and onions until they are softened and slightly charred.
Remove the vegetables from the skillet, add the remaining oil, and sear the steak strips for 2-3 minutes until browned and cooked through.
Wipe the skillet clean, place the tortilla in the pan, and sprinkle the Monterey Jack cheese over one half of the tortilla.
Layer the cooked steak and sautéed vegetables over the cheese, then fold the tortilla in half to close.
Cook for approximately 2 minutes per side until the tortilla is golden brown and the cheese has completely melted.
Garnish with fresh cilantro before slicing into wedges and serving immediately.