Start by marinating the flank steak. Combine chili powder, sea salt, black pepper, smoked paprika, onion powder, garlic powder, ground cumin, and cayenne pepper in a mixing bowl. Rub this spice mixture all over the steak and let it marinate for at least 30 minutes, or up to overnight in the refrigerator for maximum flavor.
While the steak is marinating, slice the red and green bell peppers, red onion, and jalapeños. Set them aside; they will add a fresh crunch to your quesadillas.
Heat a skillet over medium-high heat. Once hot, add the flank steak and cook for about 5-7 minutes on each side or until it reaches your desired level of doneness. Once cooked, remove the steak from the skillet, let it rest for a few minutes, then slice it thinly against the grain.
In the same skillet, add a splash of oil if needed, then toss in the sliced bell peppers, red onion, and jalapeños. Sauté for about 5 minutes or until they are tender and slightly caramelized.
Lay a tortilla on a clean surface. On one half of the tortilla, layer some sautéed vegetables, sliced flank steak, and a generous sprinkle of Monterey Jack and queso blanco. Fold the tortilla over to create a half-moon shape.
Return the quesadilla to the skillet over medium heat. Cook for about 3-4 minutes on each side or until the tortilla is golden brown and the cheese is melted. Repeat with remaining tortillas and filling.
Slice the quesadillas into wedges and serve immediately with a drizzle of chipotle vinaigrette and a side of sour cream or Mexican crema for dipping. Enjoy the explosion of flavors in every bite!
