1 1/2 cups uncooked medium grain rice (e.g., Calrose)
3 cloves garlic, crushed through a press or finely minced
1 bunch green onions, minced
3 tablespoons dried oregano
1/2 cup boiling water + more, if necessary
Place the lamb chop in the bottom of a wide stock pot and cover the shank in 2 cups of water. Turn the heat to high, bring it to a simmer, then drop the heat to low and simmer covered for 30 minutes. *
Soak the rice in cold water for about 5 minutes, then rinse it until the water runs clear.
Use your hands to mix the ground beef, salt, black pepper, rinsed medium grain rice, garlic, green onion, dried oregano, and eggs, just until combined.
Roll the meat mixture into about 20 balls (halfway between a golf ball and a tennis ball, or about the size of an average lemon). Wetting your hands while rolling helps with the process.
After simmering the lamb chop for 30 minutes, nest the meatballs in the pot on top of the lamb chop, in 1 or 2 layers.
Keep the heat at medium-low, cover, and simmer/steam the meatballs for 50 minutes. Check on them about 30 minutes in to see if the water level is too low. If it looks like it’s in danger of boiling off, add 1/2 cup more, and continue to keep an eye on it. The water should come at least 1/4- to 1/2-way up the sides of the first level of meatballs.
After 50 minutes, remove from heat and serve immediately, or keep them covered and let them rest for no longer than 45 minutes.
* If you don’t have a lamb shank, skip the first step and fill a stock pot with 2 cups of water and 2 tablespoons butter or olive oil. Bring the water and butter to a simmer before adding the meat balls.