Preheat the oven to 400F on convection mode (or 425F regular bake).
Make the tzatziki: In a medium bowl, mix together the Greek yogurt, grated cucumber, garlic, lemon, olive oil, and salt. Set aside in the fridge.
Wash the rice until the water runs clear, and then drain it with a fine mesh sieve. Transfer to a medium pot and add the chicken stock, salt, and garlic. (If you skipped washing the rice, add 2 more Tbsp stock). Bring to a boil over high heat, then cover and simmer on low heat for 15 mins. Remove the pot from the heat and let rest, covered, for 10 mins, then stir in the lemon zest, dill, and butter.
Meanwhile, make the meatballs. In a small bowl combine the panko and milk and set aside for 10 mins until the panko absorbs the milk. To a large bowl, add the ground chicken, red onion, garlic, mint, egg, lemon zest, oregano, cumin, coriander, salt, and pepper. Add the hydrated breadcrumbs (discarding any milk that didn’t get absorbed), and mix until all ingredients are evenly distributed.
