Preheat oven to 350°F.

Once your pesto is made, bring a large pot of salted water to a boil. While you prep the rest of the dish, cook the pasta until just shy of al dente, then drain and set aside. Steam the broccoli until just tender and set that aside as well.

Heat a large, oven-safe skillet or Dutch oven over medium heat. Add a drizzle of olive oil and 1 tablespoon of butter. Add the chicken and cook until golden and fully cooked through. Transfer to a plate, set aside, and dice.

In the same pan, add another 1 tbsp butter. Sauté the diced onion with a pinch of salt, pepper, oregano, and Calabrian chilies until softened, about 4–5 minutes.

Add the minced garlic and cook for another minute until fragrant. Deglaze the pan with a splash of white wine (if using), scraping up any browned bits. Let it reduce slightly.

Lower the heat, then stir in the heavy cream and walnut pesto. Let the mixture warm through, then begin adding the Parmesan and mozzarella in batches, stirring well after each addition until fully melted and smooth. Be sure to reserve a bit of each cheese for topping later.

Add the cooked pasta, steamed broccoli, and cooked chicken into the sauce. Stir until everything is evenly coated.

Top with the reserved mozzarella and Parmesan. Add spoonfuls of ricotta across the top and drizzle with a little olive oil. Note: If you're not using an oven-safe skillet, transfer the mixture to a greased 9x13 baking dish before topping.

Bake at 350°F for 15 minutes, then finish under the broiler for 2–5 minutes (depending on your broiler) until golden and bubbling.

Serve warm and enjoy!