Spread the chopped walnuts over a rimmed baking sheet so that they are in a single layer.
Bake the walnuts for 10 minutes, tossing them twice during that time. To toss, use a spatula to flip the walnuts over.
Add the toasted walnuts to the bowl of a food process and process until they are finely ground, but not a paste.
Using a spoon or your hands, combine the ground beef, finely diced onion, minced garlic, turmeric, and kosher salt in a medium sized bowl.
Form meatballs by taking a little less than a tablespoon of the beef mixture and rolling it between your hands. If any onion pieces are sticking out too much, just push them or let them fall out. Repeat this process until you’ve used all of the beef. This should make 20-25 meatballs.
Heat a skillet over high heat. If you are using lean ground beef, add about ½ tbsp of oil to the skillet. If you are using fattier beef (anything less than 80% lean), do not add any oil. Place the meatballs into the skillet (you will likely need to do this in 2 batches) and cook until browned, turning to brown each side.
Add 5 cups of water and the ground walnuts to a large pot. Heat to a boil, and once boiling reduce to a steady simmer. Simmer, stirring occasionally, for 30 minutes.
Stir in ¾ cup of the pomegranate molasses and stir well to combine. Simmer for 45 minutes. A thin oil layer will appear at the top. If it has appeared after 45 minutes, continue to the next step. If not, simmer for an additional 15 minutes.
Taste the stew and add up to another ¼ cup of pomegranate molasses if desired. I added an extra 1 tbsp.
Add the meatballs to the stew and stir to combine. Simmer for 10 minutes.
Serve with rice, feta cheese, and additional pomegranate molasses if desired.