Pre heat oven to 120°C.
1. Combine the cumin and ground coriander on a plate. Press each chicken thighs into the spice mixture and turn to evenly coat both sides. Heat the oil in a large non-stick frying pan over medium-high heat. Add the chicken thighs and cook for 4 minutes each side or until brown and cooked through. Prior to removing chicken from pan, squeeze lemon juice over the top to marinate the chicken, quickly turning the pieces to ensure all the juices are soaked up.Transfer chicken to a plate and set aside for 15 minutes to cool. Shred the chicken into thin strips and place in a large bowl.
2. While the chicken is cooking, use a sharp knife to cut down the length of the corncob, close to the core, to remove the kernels. Cook the kernels in a small saucepan or microwave until tender [approx 4 minutes]. Drain. Add to the bowl with the chicken.
3. Add the capsicum, coriander, green shallot, chili (if using) and cheese to the chicken mixture and stir until well combined. Season with salt & pepper.
4. To cook your quesadillas, heat a medium non-stick frying pan over medium-high heat. Place1 tortilla in the frying pan.
5. Top with 3 – 4 generous spoonful's of the chicken mixture and spread evenly over the tortilla. Place another tortilla on top and continue to cook for 2 minutes or until golden underneath. Turn and cook for a further 1-2 minutes or until golden and heated through. Transfer to a baking tray. Cover with foil and place in preheated oven to keep warm. Repeat with the remaining tortillas and chicken mixture, reheating and greasing pan between batches.
6. To make guacamole, place onion in food processor, blitz on high until finely chopped. Add in avocados, blend on medium speed for 1 minute. Add in tomatoes & pulse until they have combined in well with guacamole. Lastly stir in lemon juice and season to taste with salt and pepper.
7. Cut the tortillas in eights and arrange on a large serving platter. Serve immediately with guacamole and sour cream.