Prepare the rice of your choice according to the package directions and keep it warm while making the meatballs.
To make the yogurt sauce, stir together the Greek-style yogurt, dill, garlic, lemon juice, kosher salt and white pepper. Fold in the pickled red onion or green onion. Refrigerate the sauce while preparing the meatballs to allow the flavors to develop.
Place the grated yellow onion and all its juice in a large bowl. Add the breadcrumbs, stir and let the mixture rest for 5 minutes so the breadcrumbs can absorb the onion juice.
Add the lamb, egg, garlic, green onions, dill, cumin, coriander, paprika, cinnamon, cayenne, kosher salt and black pepper. Mix gently with your hands just until evenly combined.
Divide the mixture into approximately 16 portions and roll them into meatballs. If the mixture feels particularly soft, refrigerate the shaped meatballs for 20–30 minutes before cooking.
Heat the avocado oil in a large skillet over medium heat. Add the meatballs in a single layer, working in batches if necessary. Cook for 8–10 minutes, turning periodically so they brown on all sides, until cooked through and the centers reach 160°F.
Divide the warm rice among four bowls. Top each bowl with lamb meatballs, cucumber and tomato. Spoon the dill yogurt sauce over the meatballs and finish with pickled or fresh red onion, additional dill and a squeeze of lemon, if desired.
Notes
Use any rice you enjoy, including white, brown, basmati or purple rice.
Adjust the cayenne depending on how spicy you want the meatballs.
Pickled red onion adds a tangy bite, but it isn’t required. Substitute a small amount of green onion in the yogurt sauce and thinly sliced fresh red onion on the bowls, or leave the onion out entirely.
The meatballs can also be served in warm pita pockets with the vegetables and dill yogurt sauce.