Cod with potatoes in lemon sauce

1/2 cup Sitia Extra Virgin Olive Oil
2 1/4 lbs salted cod (preferably filleted) or fresh cod
2 1/4 lbs potatoes, peeled and cut into quarters
1 large onion, finely chopped
3 garlic cloves, finely chopped
3 tablespoons lemon juice
pepper

Cut the cod into serving portions and place in a large bowl filled with cold water. Soak the cod for 15 - 18 hours, changing the water 3 - 4 times.

When the fish is ready, heat the olive oil in a large pot and soften onions until they gain a little color. Add potatoes, garlic and 2 cups water and simmer for 15 minutes. Place the cod on top of the potatoes and cook gently for a further 20 minutes, shaking the pot from time to time. Five minutes before the food is ready, pour lemon juice over the food and shake the pot.

If you prefer a thicker sauce, you can dilute one tablespoon of flour in a little water and add it to the pot along with the lemon juice.