5 tablespoons extra-virgin olive oil, plus more for drizzling
1/2 onion, chopped
4 cloves garlic, smashed
1/4 to 1/2 teaspoon red pepper flakes
2 tablespoons tomato paste
2 cups low-sodium chicken broth
1/2 cup grated parmesan cheese, plus 1 piece cheese rind (optional)
8 ounces orecchiette or other small pasta
2 14 -ounce cans lentils (1 undrained; 1 drained and rinsed)
1/3 cup roughly chopped fresh parsley
Crusty bread, for serving (optional)
Heat the olive oil in a large pot over medium heat. Add the onion, garlic and red pepper flakes and cook, stirring occasionally, until the onion is slightly soft, about 2 minutes. Remove 1 tablespoon of the flavored oil and set aside. Add the tomato paste and cook, stirring, 2 more minutes. Add the chicken broth, 4 cups water and the cheese rind, if using. Bring to a boil, then add the pasta and cook, stirring occasionally, 5 minutes. Add the lentils along with the liquid from one of the cans; reduce the heat to medium low and simmer until the pasta is tender, 10 to 12 more minutes.
Meanwhile, whisk 1 tablespoon parsley and 1 tablespoon water into the reserved flavored oil. Stir 1/4 cup parmesan and the remaining parsley into the soup; remove the cheese rind (if using) and add salt to taste. Ladle into bowls; drizzle with the flavored oil and top with the remaining 1/4 cup parmesan. Serve with bread, if desired.