Bring a large pot of salted water to a rolling boil. Add 8 oz of penne pasta and cook until al dente, about 8-10 minutes. Drain the pasta, reserving ½ cup of pasta water, and set aside.

In a large skillet, heat 2 tablespoons of olive oil over medium-high heat. Season the sliced chicken with salt, pepper, and thyme. Cook the chicken for 5-7 minutes, or until golden brown and fully cooked. Remove from skillet.

In the same skillet, reduce heat to medium and melt 2 tablespoons of butter. Add garlic and sauté for about 30 seconds. Add sliced mushrooms and cook for 4-5 minutes. Then add asparagus and sauté for another 3-4 minutes until tender.

Pour in 1 cup of heavy cream, stirring to combine. Let simmer for 2-3 minutes until thickened. Gradually stir in Parmesan cheese and reserved pasta water as needed.

Return the cooked chicken and drained pasta to the skillet. Toss together to coat in the sauce. Stir for 1-2 minutes until heated through.

Serve hot, garnished with fresh parsley if desired.