1. Place oil into a sauce pan with onions and garlic, and cook over medium heat until translucent but not brown (about 10 minutes). Add the thyme and carrot; cook 5 minutes more. Add the tomatoes. Bring to a boil and then lower the heat to just bubbling, stirring occasionally for 30 minutes.
2. Season with salt to taste. Serve immediately or set aside for further use. The sauce may be refrigerated for up to 1 week or frozen for up to 6 months.
