This quick and easy tomato sauce is the base for two meals: spaghetti marinara and steamed mussels with tomato broth. We call for canned tomatoes because most of the fresh ones available in the wintertime have a bland flavor and mealy texture. Sugar will help round out the flavor if your tomatoes are too acidic. You can also add a pinch of red pepper flakes if you like your sauce to have a bit of heat. The leftover sauce also freezes well for future meals.

Ingredients

• 2 medium onions, finely chopped
• 4 garlic cloves, finely chopped
• 6 tablespoons extra-virgin olive oil
• 2 (28- to 32-ounce) cans whole tomatoes in juice
• 1 teaspoon salt, or to taste
• 1 teaspoon sugar (optional), or to taste

Preparation

1. Cook onions and garlic in oil in a 4- to 5-quart heavy saucepan over moderately low heat, stirring, until softened, 6 to 8 minutes.
2. Add tomatoes, including juice, and salt, then simmer gently, uncovered, stirring and mashing tomatoes with a fork occasionally, until sauce is thickened and reduced to about 5 cups, 1 to 1 1/4 hours.
3. If sauce tastes too acidic, add sugar and cook 5 minutes more.

Makes about 5 cups

Note:
Sauce can be made up to 5 days ahead, and can be frozen in an airtight container 3 months.