In a large bowl, pour the water. Soak the bread slices and squeeze out excess water. Discard the water.
In the same bowl, thoroughly combine the moistened bread with all the other ingredients, except the oil. Season with salt and pepper. With your hands, roll small meatballs of approximately 2 tbsp each. (You should have about 30 meatballs.)
In a large non-stick skillet over medium high-heat, brown the meatballs in the oil. Set aside.
In a saucepan, brown the onion in the oil. Add the tomatoes (or tomato sauce) and cook until softened. Add the tomato paste and curry paste and cook for 2 minutes, adding a little water if the mixture starts to stick to the saucepan. Add the coconut milk, potatoes and meatballs. Bring to a boil.
Cover and simmer for about 45 minutes, until the meatballs and the potatoes are tender.
Delicious with Spiced Rice Pilaf (see recipe below) and naan or chapati.