Sauté: Heat 1 tbsp olive oil in a skillet. Sauté onions and peppers until soft (5 mins). Stir in corn and optional spinach until wilted.
Combine: Add the cooked chicken and spices to the skillet. Stir for 2 minutes until fragrant and warm. Remove filling from the pan.
Assemble: On half of each tortilla, sprinkle a little cheese, add 1/4 of the chicken mixture, and top with more cheese. Fold in half.
Crisp: Wipe the skillet, add a drop of olive oil, and toast each quesadilla over medium heat for 3 minutes per side until golden and the cheese has melted.
Serve: Slice into wedges and serve with Greek yogurt and fresh salsa.