Place a large, heavy pot (such as a Dutch oven) over medium heat. Add 3 tablespoons extra virgin olive oil, 1 cup chopped onion, and 1 cup chopped celery and stir. Cover the pot and cook 5 minutes to soften the vegetables.

Stir in 2 teaspoons grated or finely chopped garlic, 3 tablespoons tomato paste, 1 teaspoon dried oregano, and ½ teaspoon crushed red pepper. Cook for about 15 seconds, until aromatic. Add ½ pound dried brown or green lentils, 1 14-ounce can chopped or crushed tomatoes, 5 cups broth, 2 teaspoons salt and black pepper to taste. Toss in the bay leaf and cheese rind, if you're using.

Turn the heat up to medium-high until the liquid comes to a boil. Reduce the heat to a simmer and cook uncovered 30-35 minutes, stirring occasionally, until the lentils are tender and the soup looks thickened. If the lentils are older, they may take up to 45 minutes. Remove the rind and bay leaf and discard.

Scoop out a generous cup of the soup and puree in a blender. You can also briefly pulse a hand blender right in the pot. At this point, you can add the remaining cup of broth if the soup seems too thick.

Add 1 teaspoon red wine vinegar and 2 tablespoons chopped parsley to the soup and stir. Taste the soup and add more salt and pepper, if needed. Serve the soup warm in bowls, with some grated cheese over each portion. Add a side of warm crusty bread for dipping!