2) In a medium saucepan, bring the chicken stock, water, and salt to a boil over high heat. Add the pasta and cook until tender but still firm to the bite, stirring occasionally, about 8 to 10 mins.
3) While the pasta is cooking: In a large skillet, heat the oil over medium-high heat. Add the turkey sausage and saute until cooked through, about 4 mins. Add the garlic and cook for 1 min. Add the peppers, tomatoes, and red pepper flakes, if using, and cook until heated through, about 2 mins.
4) Drain the pasta, reserving about 120ml of the cooking liquid, and transfer to a large serving bowl. Add the sausage mixture, 1 tbsp of the parsley, and season with salt and pepper, to taste. Toss well to combine all ingredients, adding reserved cooking liquid, if needed, to loosen the pasta. Top with the ricotta salata and sprinkle with the remaining parsley. Serve.