Heat the olive oil in a medium pot over medium heat. Add the onions, garlic, salt, basil, oregano and black pepper, and cook, stirring, until soft, 4 minutes. Add the tomatoes and their juices, the tomato paste, water, and sugar, and stir well. Bring to a boil. Lower the heat to medium-low and simmer uncovered until thickened and fragrant, about 30 minutes, stirring occasionally. Remove from the heat and adjust the seasoning to taste. Use as needed to top pasta or pizza.