Mix the meatball base: In a large bowl, combine ground turkey, breadcrumbs, egg, grated onion, minced garlic, parsley, Italian seasoning, paprika, salt, and pepper.
Use a fork or your hands to gently mix until just combined. Do not overwork the meat.
Shape the meatballs: With damp hands or a small scoop, form 16–20 meatballs, about 1 to 1 1/2 inches each. Place them on a plate or parchment-lined sheet.
Preheat your skillet: Heat a large nonstick or cast-iron skillet over medium heat.
Add 1 tablespoon olive oil and swirl to coat.
Sear the meatballs: Add meatballs in a single layer without crowding. Cook 6–8 minutes, turning every couple of minutes to brown all sides. Add a bit more oil if the pan looks dry.
Check doneness: Turkey meatballs are done when the centers reach 165°F (74°C).
If they brown too quickly, lower the heat and cover the pan for 2–3 minutes to finish cooking.
Transfer and rest: Move the cooked meatballs to a plate and tent loosely with foil.
Make the garlic butter sauce: Reduce heat to medium-low. Add butter to the skillet. When melted, stir in minced garlic and cook for 30–45 seconds until fragrant, not browned.
Deglaze: Pour in the chicken broth (or wine) and scrape up browned bits with a wooden spoon.
Simmer 2–3 minutes to reduce slightly.
Finish the sauce: Stir in lemon juice, parsley, and a pinch of red pepper flakes. Taste and season with salt and pepper as needed.
Coat the meatballs: Return the meatballs to the skillet and spoon the sauce over them. Simmer 1–2 minutes to warm through and let flavors mingle.
Serve: Plate with pasta, rice, or crusty bread.
Spoon extra garlic butter over the top and finish with more parsley or Parmesan if you like.