Beans are the Secret in This Sauce UncategorizedBean Bulletin, Tips Let beans be the secret ingredient in your next batch of rich tomato sauce. Adding beans to tomato sauce is an easy way to create a sauce that is extra thick, and also packed with protein. If you have picky eaters in your family, it’s a good way to sneak health-promoting beans into their diet, too. Choose canned or well-cooked beans and puree them thoroughly in a food processor. Then stir in ¼ to ½ cup of beans for each cup of tomato sauce, depending on how thick you want it to be. Any type of bean works for this.