Michael Romano's Secret-Ingredient Soup

INGREDIENTS

• 2 tablespoons olive oil
• 1/4 teaspoon Aleppo pepper or red pepper flakes
• 2 tablespoons medium-grind cornmeal (polenta)
• 4 cups packed stemmed and coarsely chopped kale or chard leaves, or a combination
• 1/4 teaspoon freshly ground black pepper
• 3/4 cup finely chopped peeled carrot
• 1 teaspoon finely chopped garlic
• Grated Parmigiano-Reggiano for serving
• 3/4 cup well-washed thinly sliced leeks
• 5 cups or Vegetable Stock
• 8 ounces Italian fennel sausage (sweet or hot), casings removed
• 1 1/2 teaspoons kosher salt
• 3/4 cup finely chopped onion