In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 3-4 minutes. Then, stir in the jalapeño pepper and continue cooking for another 2 minutes until softened.
Sprinkle in the kosher salt, chili powder, and ground cumin. Stir well to combine, allowing the spices to toast slightly in the pan.
Next, add the shredded cooked chicken, salsa, and lime juice to the skillet. Mix everything together and cook for an additional 3-5 minutes until heated through and well combined. Remove from heat and stir in the shredded Monterey Jack cheese.
In a separate skillet, heat a small amount of vegetable oil over medium heat. Lightly fry each tortilla for about 10-15 seconds on each side until softened, making them easier to roll.
Spoon a generous amount of the chicken mixture onto each tortilla and roll tightly. Secure the ends with toothpicks if needed.
In the same skillet used for the tortillas, add enough vegetable oil to cover the bottom. Once hot, carefully add the rolled flautas, seam side down. Fry for about 3-4 minutes on each side or until golden brown and crispy. Remove and drain on paper towels.
Serve the Chicken Flautas hot with additional salsa, guacamole, or sour cream on the side for dipping. Enjoy the crispy texture and delightful flavors!