Beef and Lentil Chili

Name: Beef and Lentil Chili
Ingredients: 1 cup French lentils (du Puy); 1 tablespoon olive oil; 1 pound ground beef; 4 oz pancetta (diced); 1 large onion (finely diced); 1 leek (rinsed, quartered and sliced); 3 cloves garlic (minced); 1 teaspoon black pepper; 1/2 teaspoon Kosher salt; 1 1/2 teaspoons cayenne pepper; 1 teaspoon cumin; 1 teaspoon paprika; 1 teaspoon oregano; 1 teaspoon marjoram; 1/4 teaspoon thyme; 3 tablespoons tomato paste; 3 stalks celery (diced); 2 carrots (diced); 7 cups low sodium chicken stock; 1 15 oz can diced tomatoes (if you desire more heat, opt for fire-roasted); 1 tablespoon balsamic vinegar; cilantro (chopped); scallions (sliced); cheddar cheese (grated)