To make salsa, combine all ingredients in a bowl. Cover and refrigerate while making quesadillas.
For the quesadillas, combine the cheese, capsicum and spring onions in a bowl. Season with pepper.
Place two of the tortillas on a board and divide the cheese mixture evenly between them, spreading almost to the edges. Place another tortilla over the filling and gently press down.
Heat a large non-stick frying pan over a medium heat. Spray lightly with cooking oil. Add one quesadilla. Spray top tortilla lightly with cooking oil. Cook for 2-3 minutes, or until lightly browned underneath. Carefully turn using an egg slide. Cook other side for 2-3 minutes, or until browned and cheese is melted. Remove from pan. Repeat with remaining quesadilla. Cut each quesadilla into six wedges.
Serve with salsa.

Serve these quesadillas and salsa as a tasty to side to grilled lean chicken or pork steaks.