1/2 cup steel-cut oatmeal
1/2 cup loosely packed fresh cilantro leaves, chopped, plus more for garnish
4 cloves garlic, minced (about 2 tablespoons), divided
1 chipotle in adobo sauce, seeded and chopped into a paste
4 teaspoons ground cumin, divided
2 teaspoons ground coriander, divided
Kosher salt and freshly ground black pepper
1/2 pound ground lamb
2 teaspoons olive oil
1 small onion, cut into 1/4-inch dice (about 1 cup)
1 (28-ounce) can crushed tomatoes
1 cup water
Juice of 1 lime
Mix together the oatmeal, cilantro, half the garlic, the chipotle, 2 teaspoons of the cumin, 1 teaspoon of the coriander, 1 teaspoon salt, and 1/4 teaspoon pepper in a bowl. Gently work the lamb into the mixture, distributing it evenly. Form balls out of tablespoon-size scoops of the mixture and set aside.
Heat the oil in a Dutch oven or a large pot over medium-high heat. Add the onion and sauté for 5 minutes. Stir in the remaining garlic, cumin and coriander, cooking for an additional 30 seconds. Add the tomatoes and water and stir to combine. Bring the sauce to a simmer and add the meatballs. Simmer partially covered for 45 minutes. Season the sauce with salt and pepper to taste, squeeze the lime juice over top, and serve with extra chopped cilantro. Serves 4 to 6.