Season the chicken supremes generously with salt and freshly cracked black pepper.
Heat a large oven-safe pan over medium heat. Add a little oil and allow it to get hot.
Place the chicken supremes skin-side down in the skillet. Sear the chicken for 3-4 minutes, until the skin becomes crispy and golden. Add the fresh thyme and 50g butter to the pan. Once the butter is melted, spoon it over the chicken to baste. Flip the chicken over and transfer the pan to the preheated oven. Roast for 15-20 minutes, or until the chicken reaches an internal temperature of 75°C.
Once cooked, remove the chicken from the oven and let it rest for 5 minutes.
In a large pot, bring salted water to a boil and cook the spaghetti until al dente, as per the package instructions. Reserve about 1 cup of pasta water before draining the spaghetti.
While the pasta cooks, toast the black peppercorns in a dry pan over medium heat for 1-2 minutes until fragrant. Use a mortar and pestle or grinder to coarsely crush the peppercorns.
Melt in the 50g of butter over medium heat.
Add a small splash of the reserved pasta water to the pan, then stir in the grated parmesan and pecorino cheeses. Continue stirring until the cheese melts and combines with the water to form a creamy sauce.
Add the drained spaghetti to the pan and toss to coat in the cheese sauce, adding more pasta water as needed to achieve a smooth, glossy texture. Serve it up with the chicken supremes and enjoy.
