Cook the pasta: Bring a large pot of well-salted water to a boil. Cook orecchiette until al dente.Reserve 1 cup / 240 ml of pasta cooking water, then drain.
Brown the sausage: Heat olive oil in a large sauté pan over medium-high heat. Add sausage, breaking it into bite-size pieces. Cook until deeply golden. Remove and set aside.
Sauté aromatics and mushrooms: In the same pan, add butter, then sauté shallot and garlic until fragrant.Add mushrooms and cook until golden and any moisture has evaporated.
Deglaze: Stir in chili flakes (if using) and white wine. Reduce until nearly dry.
Add cream and sausage: Lower heat to medium-low. Add cream and return sausage to the pan.Simmer gently for 3–4 minutes, without boiling.
Combine and emulsify: Add cooked pasta and a splash of reserved pasta water. Toss until the sauce coats the pasta evenly and becomes glossy.
Finish: Fold in spinach until just wilted. Remove from heat and stir in Parmigiano Reggiano, black pepper, lemon zest and juice. Adjust seasoning and consistency with additional pasta water if needed.
Time to plate, garnish with Parmigiano shavings and enjoy. Bon Appétit :)