Food & Cooking Recipes Tomato and Onion Vinaigrette 3.0 (3) Add your rating & review By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on September 28, 2016 Print Rate It Share Share Tweet Pin Email Ingredients 1 pound plum tomatoes, finely chopped 1 small green bell pepper, finely chopped ½ large white onion, finely chopped 1 cup white vinegar ⅓ cup extra-virgin olive oil 2 teaspoons coarse salt ¼ teaspoon ground black pepper 1 teaspoon granulated sugar Directions Place all ingredients in a medium bowl and stir to combine. Let stand at room temperature for at least 2 hours and up to 8 hours, stirring occasionally. Cook's Notes Vinaigrette can be made up to 1 week ahead and stored in an airtight container in the refrigerator. Cook's Notes Vinaigrette can be made up to 1 week ahead and stored in an airtight container in the refrigerator. Rate it Print