1
In a large skillet, heat half of the olive oil on high heat. Add the sausage and cook until caramelized, breaking it up with a wooden spoon. Remove the sausage from the pot.
2
Add the remaining oil to the skillet and heat over medium-low with the garlic. Toast until golden. Add the chile flakes and toast for 1 minute. Add the onions and lower the heat. Cook until fragrant and soft.
3
Add the carrots and celery and cook until soft, another 5-10 minutes. Add the tomato purée and simmer for 1 hour on low heat. Season with salt to taste. Turn off the heat and fold in the herbs.
4
Towards the end of the cooking time, =bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions. Drain the pasta, return to the pot, and drizzle with olive oil to prevent sticking.
5
Toss the pasta with the sauce, divide between bowls and garnish with herbs and ricotta salata.