1Stir chicken broth, water, carrots, celery, onion, lentils, garlic, and red wine vinegar together in a large stockpot; bring to a boil, reduce heat to low, and cook at a simmer until the carrots are tender, about 10 minutes.
2Stir ham, mustard, salt, and pepper into the soup; continue cooking until the lentils are tender, 20 to 30 minutes more.
Footnotes
Cook's Notes:
Just before serving, sprinkle some grated Parmesan cheese on top.
For added smoky flavor, add 1 to 2 teaspoons paprika.
Tip
Aluminum foil helps keep food moist, ensures it cooks evenly, keeps leftovers fresh, and makes clean-up easy.