Soak fish in water for 24 hours. Drain and put fresh water to cover. You can repeat this process if the cod is still too salty.
Boil until fish is tender, about 20 minutes. Drain. Once it is cool enough to handle, flake by hand.
In a large skillet, heat oil. Add onion and garlic and saute for a few minutes, until onions are translucent. Add tomatoes and wine and cook on medium-high heat for about 3-4 minutes, until alcohol has been cooked out.
Add fish and parsley. Toss and cook for 1-2 minutes.
Add pepper and lemon juice and toss to combine.
Serve, garnished with more parsley, with crusty Italian bread or roasted potatoes.