In a medium bowl, add the chicken, parmesan, ¼ cup oats, grated onion, dill, cumin, ½ teaspoon turmeric, and 1 teaspoon salt. Shape the meat into small balls, about 2 inches.
Heat the oil in a dutch oven over medium heat until shimmering. Add the diced onion, season with salt, and cook until it softens, about 2 minutes, stirring occasionally. Add the remaining 1 teaspoon turmeric and the red pepper flakes, and stir until fragrant, about 30 seconds. Push the onions to the sides, then add the meatballs. Cook 5-7 minutes until browned on two sides.
Add the broth and ½ cup oats. Bring to a gentle boil, then reduce the heat to maintain an active simmer. Season with salt. Stir occasionally to ensure nothing sticks to the bottom until the oats have softened and the meatballs are cooked through, about 4 minutes.
Add the spinach and lemon juice until the spinach is wilted, about 2 minutes. Adjust the seasoning to taste. Spoon into bowls. Serve with lemon wedges and dill.