To prepare the chile paste, remove stems and seeds from all chile pods and place pods in hot water; soak for at least 2 hours, until they are softened. Drain and place chiles in a food processor or blender; pulse until they form a paste-like consistency. Divide the chile paste, reserving half for the meatballs and half for the sauce.

Preheat oven to 375°F.

To prepare meatballs, heat a skillet over medium-high heat, and sauté onion in

1 tablespoon cooking fat for 3–5 minutes, until translucent. Set aside and divide onions, half for the meatballs and half for the sauce.

In a small bowl, combine milk and breadcrumbs and stir to form a panade. Let sit 3–5 minutes to hydrate fully.

In a large bowl, combine onion, meat, half the chile paste, garlic, seasonings, olive oil, salt, egg, and panade. Mix with your hands until combined—do not overwork the mixture. Let sit for 10 minutes to allow the panade of milk and breadcrumbs to hydrate. With wet hands, roll meat mixture into lime-sized meatballs (or your preferred size).

In a large, shallow baking dish or sheet pan, place meatballs in a single layer, leaving a little space between them for even browning. Bake for 12 minutes, or until just set but not browned.

While meatballs are baking, prepare the sauce. In a large skillet over medium-high heat, combine reserved cooked onion, garlic, reserved chile paste, coriander, smoked paprika, sumac, and bay leaves. Stir together and add tomato puree and salt. Bring to a boil, then turn off the heat. Sauce should be thick but pourable.

Place the desired number of meatballs in the sauce, return to medium-low heat, and simmer for 20 minutes. If the sauce becomes too thick, add up to 1/2 cup of water.

Serve over rice, couscous, mashed potatoes, or polenta.

To make ahead: Bake meatballs and cool completely. Refrigerate in shallow, airtight container for up to 4 days, or freeze for up to 6 months. Refrigerate the sauce separately for 4 days, or freeze for up to 6 months. Reheat meatballs by simmering in a sauce or lightly browning in a skillet with oil.