Catfish or tilapia can be used instead of the ling in this recipe (or other recipes that call for ling). Here the fish is simmered with a fragrant mix that includes onion, bell pepper, saffron, white wine, and bay leaf until cooked through and a sauce has formed. While the fish is cooking, you can boil and then saute the potatoes that are served alongside. Round out the meal with a watercress salad.