In a microwavable bowl, cover the ancho chiles with the water, then cover the bowl and microwave the chiles on high for 2 minutes. Transfer the chiles and 1/2 cup of their soaking liquid to a blender. Add the tomatoes, 2 of the garlic cloves, 2 of the scallions, 1 teaspoon of the cumin, the coriander and the chicken stock. Season the chile sauce with salt and pepper and puree until smooth.
In a large bowl, mix the pork and beef with the eggs, Parmesan, bread crumbs, thyme, 1 tablespoon of kosher salt, 1/4 teaspoon of pepper and the remaining 2 garlic cloves, 2 scallions and 2 teaspoons of cumin. Form the meat into 18 meatballs.
In a 10-inch cast-iron skillet, heat the oil until shimmering. Add the meatballs and cook over moderately high heat until browned all over, about 6 minutes. Add the peppers and cook, stirring occasionally, until softened, 2 to 3 minutes. Add the chile sauce and bring to a boil. Simmer over moderate heat until the sauce is thickened and the meatballs are cooked through, about 10 minutes. Serve at once.
Serve With: Sliced bread and crumbled farmer cheese.