In a large mixing bowl, combine 1 pound of ground chicken with 1/2 cup breadcrumbs, 1/4 cup grated Parmesan, 1/4 cup chopped fresh parsley, 1 clove minced garlic, 1 large egg, 1 teaspoon salt, and 1/2 teaspoon black pepper. Mix gently until just combined.
Shape the mixture into 1 1/2-inch meatballs and set them aside on a plate. You should get about 16 meatballs.
Heat 2 tablespoons olive oil in a large skillet over medium heat. Add the meatballs in batches, leaving space to brown evenly. Cook for 3-4 minutes on each side until golden but not fully cooked through. Transfer meatballs to a plate.
In the same skillet, add 1 cup chicken broth, scraping up browned bits. Stir in 1/4 cup fresh lemon juice and 2 tablespoons capers. Bring sauce to a simmer.
Return meatballs to the skillet, nestle into sauce, cover and simmer for 8-10 minutes until cooked through.
Remove lid and stir in 1 tablespoon butter until melted, creating a silky sauce. Taste and adjust seasoning if needed.
