In a large bowl, combine the ground chicken, Parmesan, panko breadcrumbs, salt, minced garlic, and lemon zest. Mix gently with your hands until just combined—don't overwork the mixture or the meatballs will become dense and tough. I find it helpful to use a light touch and stop mixing as soon as everything is evenly distributed. Set the bowl aside and prepare a clean surface for rolling.

Roll the meat mixture into balls using about 2 tablespoons per meatball (you should get about 12-14 meatballs). Heat the olive oil in a large skillet over medium-high heat until shimmering. Working in batches if needed to avoid crowding, add the meatballs to the pan and cook for 6 minutes, turning them occasionally to ensure even browning on all sides. Transfer the cooked meatballs to a clean plate and set aside.

In the same skillet, reduce heat to medium and add the butter and minced garlic. Let the butter melt and the garlic become fragrant, about 1-2 minutes. Sprinkle the flour over the butter and garlic, whisking constantly to create a smooth paste (this is your roux). Cook the roux for about 1 minute to remove any raw flour taste. I like to let the garlic bloom in the butter first before adding flour so the garlic flavor is more subtle and integrated.

Slowly whisk the chicken broth into the roux until smooth and no lumps remain. Add the capers, caper brine, and lemon juice, stirring well to combine. Bring the sauce to a gentle simmer and cook for 6-7 minutes until it thickens slightly and the flavors meld. Return the meatballs to the pan, nestling them into the sauce, and simmer for another 5-6 minutes until the meatballs are heated through and the sauce coats them beautifully.

Remove the pan from heat and taste the sauce for seasoning, adjusting salt and lemon juice as needed. Transfer the meatballs and sauce to a serving dish or individual plates, then garnish generously with fresh parsley. The bright acidity from the capers and lemon juice should balance beautifully with the richness of the butter and Parmesan-studded meatballs.