Heat the oil in a medium pot over medium-low heat. Add the onion, garlic, tomatoes, and parsley. Sprinkle lightly with salt and pepper. Stir to mix. Cover and cook, stirring occasionally, for 15 minutes, or until the tomatoes are soft and have released their juices.
Add the water. Raise the heat to high, cover, and bring to a boil. Remove the cover and lower th