Can't make up your mind whether to make bean or lentil soup? Grab a bag of 15-bean soup from the dry goods aisle at the market and make this flavorful, hearty soup instead. Bean and lentil soups like this one are often cooked with a ham bone or a smoked ham hock, but there are other ways to add flavor to a pot of soup, especially when you want something vegetarian. Here, we add a few Parmesan cheese rinds, which add a surprising depth of flavor and umami when simmered with a pot of soup, stew, or even pasta sauce. If you aren't yet in the habit, when you are done with that wedge of Parmesan cheese, toss the rind in an airtight container and store in the freezer to be at the ready. Your soups and stews will thank you for the flavor boost. Serve this hearty soup with a loaf of warm crusty bread.