Prepare the Tzatziki Sauce: In a bowl, combine Greek yogurt, grated cucumber, garlic, olive oil (if using), lemon juice, and dill. Season with salt and pepper to taste. Stir well, then cover and refrigerate while preparing the meatballs.
Preheat your oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
Make the Meatballs: In a large bowl, combine ground chicken, shallots (or red onion), egg, olive oil, bread crumbs (or almond flour/pork rinds), lemon zest, lemon juice, garlic, parsley, oregano, dill, onion powder, Greek yogurt, salt, and black pepper.
Mix until just combined—avoid over-mixing to keep the meatballs tender. If the mixture is still too wet, add a little more bread crumbs until you get the correct conistnecy. Roll the mixture into 1 ½-inch meatballs and place them on the prepared baking sheet.
Bake for 20-22 minutes, or until the meatballs are golden brown and reach an internal temperature of 165°F. If you want a nice crispy crust, broil for the last 2-3 minutes. Make sure to keep a close eye so they don't burn.
Serve: Spread a generous layer of tzatziki sauce on a serving plate or shallow bowl. Spread a generous layer of tzatziki sauce on a serving plate or shallow bowl. Arrange the warm meatballs on top of the sauce.
Garnish with extra fresh dill, parsley, or a drizzle of olive oil if desired. Serve with warm pita, a side salad, or roasted vegetables.