1/2 cup olive oil, divided
4 large links of sweet Italian sausage, casings removed (I used half of this, preferring the sausage to not dominate the soup’s flavor)
1 medium onion, diced
2 celery stalks, sliced or diced
2 medium carrots, peeled and sliced into half-moons or diced
4 cloves garlic, sliced (reserve half for later in recipe)
Kosher salt
A pinch of crushed red pepper flakes (optional)
1 cup brown lentils, sorted and rinsed
2 bay leaves
1 28-ounce can crushed tomatoes
6 cups water
Freshly ground black pepper
3 to 4 cups shredded or thinly ribboned Swiss chard leaves or kale
Grated Pecorino Romano cheese to finish