Prepare all ingredients as listed.
Heat olive oil in a non-stick pan over medium heat. Add the onion and green bell pepper and sauté until softened.
Add the chicken, paprika, garlic powder, and ground cumin. Season with salt and black pepper. Cook, stirring occasionally, until the chicken is browned and reaches an internal temperature of 165°F (74°C). Remove from heat.
Place the tortillas on a work surface and sprinkle Monterey Jack cheese evenly over one side of each tortilla.
Spoon the cooked chicken mixture over the cheese, then fold the tortillas in half to enclose the filling.
Heat a clean non-stick pan over medium-low heat with a light drizzle of olive oil. Cook the quesadillas until golden brown on both sides and the cheese is melted.
Combine the sparkling water and lemon slices and stir gently.
Serve the chicken quesadilla with lemon sparkling water.