1. In a pot over medium-high heat, soften the celery, carrots, garlic and leek in the oil. Add the sausage meat and cook for 5 minutes, breaking it up with a wooden spoon. Sprinkle with the flour and toss well to coat the vegetables and meat. Add the broth. Bring to a boil while stirring constantly. Simmer to reduce the sauce for 30 minutes over medium-high heat, or until the sauce thickens. Set aside 2 cups (500 ml) of the sauce.
2. Meanwhile, in a large pot of salted boiling water, cook the pasta until al dente. Drain and lightly oil.
3. Add the pasta, peas and 3/4 cup (55 g) of the Parmesan to the pot of sauce. Cook for 1 minute or until the pasta has soaked up the cooking juices. Serve the pasta in bowls. Top with the reserved sauce and remaining Parmesan.

NOTE FROM RICARDO

The cavatelli should be bathing in the cooking juices. This dish is eaten like a soup or stew. Because the pasta tends to absorb everything, we recommend setting aside a portion of the sauce to be added just before serving.