Preheat your oven to 375°F and spray a 9x13 inch casserole dish with cooking spray. While the oven heats, prepare your mise en place: mince the garlic cloves, squeeze the lemon juice fresh (you'll need about 1/3 cup), slice one lemon into thin rounds, chop the fresh parsley, and have your capers measured and ready. Pound the chicken breasts to an even 1/2-inch thickness, then cut them into 1-inch strips. Having everything prepped before you start cooking ensures the dish comes together smoothly.

Melt the butter in a medium skillet over medium heat. Once foaming, add the minced garlic and flour together, stirring constantly for about 1 minute to create a light roux—this step is crucial as it removes the raw flour taste and begins to thicken your sauce. Pour in the chicken broth and half-and-half, stirring continuously to prevent lumps from forming. Increase heat to medium-high and let the mixture come to a gentle boil, stirring frequently, until it thickens noticeably (about 5 minutes). The sauce should coat the back of a spoon when ready.

Remove the skillet from heat and stir in the 1/2 cup Parmesan cheese, fresh lemon juice, and capers. The residual heat will melt the cheese smoothly without any risk of curdling the half-and-half. Season generously with salt and black pepper to taste—I like to go a bit heavier on the pepper here since it complements the bright lemon and briny capers beautifully. The sauce should be smooth, rich, and vibrant with flavor.

Place the cut chicken strips in the prepared casserole dish and season them lightly with salt and pepper. Pour the piccata sauce from Step 3 evenly over the chicken, making sure all pieces are well coated. Arrange the lemon slices on top of the sauce, distributing them across the surface for visual appeal and extra flavor.

In a small bowl, combine the 1/3 cup Parmesan cheese and panko bread crumbs, mixing them together evenly. Sprinkle this mixture generously over the entire casserole to create a golden, crispy topping. Place the casserole in the preheated 375°F oven and bake for 20-25 minutes until the chicken reaches an internal temperature of 165°F (check the thickest piece with a meat thermometer) and the topping turns golden brown. I find that panko gives a noticeably better crunch than regular breadcrumbs, making the casserole feel more restaurant-quality.

Remove the casserole from the oven and let it rest for 2-3 minutes. Sprinkle the fresh chopped parsley over the top just before serving for a pop of color and fresh herbaceous flavor. Serve warm directly from the casserole dish or portion into individual bowls.