Preheat the oven to 270°F.

Cook the pasta in boiling salted water for 2 minutes less than the cooking time on the package. Reserve ⅓ cup of the pasta cooking water for later. Drain the pasta and run under cold water to stop the cooking process. 

Generously season the chicken with salt and pepper. Set a heavy-bottomed, oven-safe pot over high heat and add 2 tablespoons of oil. Sear the chicken until deeply golden, 5-7 minutes on each side. Remove from the pot and set aside.

In the same pot over medium-high heat, add ½ cup of neutral oil. Add the onion with 1 tablespoon of salt and sauté until translucent and lightly golden, about 5–7 minutes. Stir in the garlic, sun-dried tomatoes, cherry tomatoes, and black pepper, and cook until the oil takes on a rich color, about 5 minutes.

Add the tomato purée and stir well to combine. Then add the pasta and stir until evenly coated with the sauce.

Transfer two-thirds of the pasta to a large bowl, leaving one-third in an even layer at the bottom of the pot. Place the chicken on top, skin side up, then add the remaining pasta over the chicken.

Add the reserved pasta cooking water. Over high heat, bring to a gentle boil, then reduce the heat and cook for 1-2 more minutes.

Lay a piece of parchment paper closely over the pasta and seal with a lid. Bake in the oven for 6 hours. 

To serve: Remove the lid and parchment paper and place a large serving platter (larger than the pot) over the top. Use oven mitts or kitchen towels and carefully flip the pot onto the platter. Lift the pot and serve immediately.