1. To make the irresistible Parmesan Dijon sauce, start by melting the butter in a saucepan over medium heat. Whisk in the flour and cook for 1-2 minutes, allowing the mixture to thicken slightly. Gradually pour in the milk while continuing to whisk, then add the chicken bouillon cube. Simmer the sauce until it has reached a desired creamy consistency.

2. Next, stir in the Dijon mustard, a dash of hot sauce (if desired), and the freshly grated Parmesan cheese. Season with salt and pepper to taste. The end result is a luxuriously smooth and flavorful sauce that perfectly complements the Chicken Cordon Bleu Quesadillas.

3. Building these Chicken Cordon Bleu Quesadillas is a breeze. Lay the tortilla on a flat surface and layer the sliced grilled chicken, ham, and cheese on one half of the tortilla. Sprinkle the toasted breadcrumbs over the top to add that irresistible crunch.

4. Fold the empty half of the tortilla over the filled half, creating a half-moon shape. This method ensures that the ingredients are evenly distributed and the quesadilla holds together perfectly when cooking.

5. To get those Chicken Cordon Bleu Quesadillas perfectly crispy, heat a skillet over medium heat and brush it with the melted butter. Carefully place the assembled quesadilla in the pan and cook for 2-3 minutes per side, or until the tortilla is golden brown and the cheese is melted.

6. Keep a close eye on the quesadillas to prevent burning, and flip them gently to maintain their shape. The key is to find that sweet spot where the tortilla is crispy on the outside and the fillings are warm and melty on the inside.

7. These Chicken Cordon Bleu Quesadillas are best served hot, straight from the pan. Cut each quesadilla into wedges and arrange them on a platter, alongside the creamy Parmesan Dijon sauce for dipping.