Bring a large pot of salted water to a boil. Cook the pasta according to the package instructions until al dente. Drain and set aside, reserving half a cup of pasta water.

While the pasta cooks, heat olive oil in a large skillet over medium-high heat. Season the chicken cubes with salt and pepper.

Add the chicken to the skillet and cook for 5 to 7 minutes until golden brown and cooked through. Remove the chicken from the pan and set it aside on a plate.

In the same skillet, add the diced onion. Sauté for about 3 minutes until translucent. Add the minced garlic and cook for another minute until fragrant.

Lower the heat to medium. Stir in the pumpkin puree, chicken broth, and heavy cream. Whisk gently until the sauce is smooth.

Stir in the dried sage, nutmeg, and Parmesan cheese. Let the sauce simmer for 5 minutes until it starts to thicken.

Add the cooked chicken and the drained pasta into the skillet. Toss everything together until the pasta is well-coated. If the sauce is too thick, add a little of the reserved pasta water.

Taste and add more salt or pepper if needed. Garnish with fresh parsley and serve hot.