How to Make It
Combine the rice, eggs, oregano, a third each of the scallions and garlic, 1/2 teaspoon of the cumin, and 1/2 teaspoon each salt and pepper in a bowl. Add the pork and gently mix with your hands until just combined. Form the mixture into 16 meatballs (about 11/2 tablespoons each). Broil, on the prepared baking sheet, until cooked through, 8 to 10 minutes.
Heat broiler. Line a rimmed baking sheet with foil.
Meanwhile, heat the oil in a large pot over medium heat. Add the remaining scallions, garlic, and cumin and 1/2 teaspoon each salt and pepper. Cook, stirring occasionally, until the scallions are tender, 1 to 2 minutes. Add the tomatoes and cook, stirring occasionally, until starting to thicken, 4 to 6 minutes.
Add the broth and bring to a boil. Stir in the spinach and meatballs. Serve topped with the cilantro, Cheddar, and a dollop of sour cream.
Tip: Cutting the vegetables into large pieces allows them to get a little golden color before softening completely. If you have small turnips, use 4 instead of 2 and roast them whole.