In a saucepan, heat the oil and cook the onions until soft
Add the garlic and basil, and cook for 30 seconds
Add the chopped tomatoes and water, season with salt and pepper, and simmer for 10 to 15 minutes until thickened
Notes
The sauce can be mashed for a finer consistency or left rustic as is. Do a taste test for seasoning and if too tart, add some sugar. If preferred, the basil leaves can be replaced with 4 tablespoons of parsley or 2 teaspoons of origanum.