Kosher salt, to taste
2 lbs. russet potatoes, peeled and
cut into 2" chunks
1⁄3 cup olive oil
1 16-oz. can whole tomatoes,
undrained, crushed by hand
1⁄2 tsp. crushed red chile flakes
5 cloves garlic, minced
2 medium yellow onions, roughly chopped
2 bay leaves, broken in half
1 medium green bell pepper, cored, seeded,
and roughly chopped
1 cup fish stock or bottled clam juice
1⁄2 cup dry white wine
Freshly ground black pepper, to taste
18 mussels, rinsed and debearded
2 lbs. boneless, skinless haddock or cod filets,
cut into 1 1⁄2" chunks
3 tbsp. minced fresh cilantro
3 tbsp. minced fresh parsley
1. Bring a large pot of salted water to a boil and add potatoes; cook, stirring occasionally, until tender, 12–15 minutes. Drain and set aside.
2. Heat the oil in a 6-qt. pot over medium-high heat. Add tomatoes, chile flakes, garlic, onions, bay leaves, and peppers and cook, stirring often, until soft, about 12 minutes. Add fish stock, wine, and salt and pepper and cook, stirring occasionally, about 5 minutes. Add mussels and cover pot; cook until mussels just begin to open, 4–5 minutes. Add fish and continue to cook, covered, until all mussels are opened and fish is cooked through, 5–6 minutes more.
3. To serve, transfer fish stew to a large serving bowl and sprinkle with half the parsley and cilantro. Place the potatoes in another serving dish, sprinkle with remaining cilantro and parsley, and serve alongside stew.