Boil salted pasta:
Fill a large pot with water, bring to a rolling boil, add a generous amount of salt, and cook the pasta until al dente following the package instructions.Heat oil and butter:
In a spacious, deep skillet, warm the olive oil over medium heat and add the butter, letting it melt.Sauté chicken pieces:
Place the chicken pieces into the pan, sprinkle with salt and pepper, and sauté for 5-6 minutes until they develop a light golden color.Cook onion and mushrooms:
Toss in the sliced onion and mushrooms, continue cooking for another 3-4 minutes until the mushrooms are tender and have shrunk.Add garlic and spices:
Mix in the garlic, red chili flakes, dried basil, and dried oregano; let cook for 1 minute.Simmer tomato sauce:
Add the tomato paste and crushed tomatoes. Let the sauce come to a simmer and allow it to bubble for 5 minutes.Toss in spinach and pasta:
Fold in the baby spinach and let it wilt for about 1 minute. Then, add the drained pasta to the pan and toss everything together.Mix in Parmesan and serve:
Mix in the grated Parmesan, adjust seasoning with salt and pepper, and serve, optionally topped with extra Parmesan.