Pat chicken cubes dry with paper towels. In a medium bowl, toss chicken with 1 tbsp olive oil, 1/2 tsp salt, 1/4 tsp black pepper, garlic powder, and Italian seasoning until evenly coated.

Bring 8 cups of salted water to a rolling boil in a large pot. Add penne pasta and cook according to package directions until al dente. Drain well, reserving 1/2 cup of pasta water, and set aside.

Heat 1 tbsp olive oil in a large skillet or Dutch oven over medium-high heat. Add the seasoned chicken and cook for 5-7 minutes, stirring occasionally, until browned and cooked through. Remove chicken from the skillet and set aside.

Add the remaining 1 tbsp olive oil and butter to the same skillet. Once butter is melted, add sliced mushrooms and cook for 5-7 minutes, stirring occasionally, until softened and browned.

Add the diced onion and asparagus to the skillet with the mushrooms. Sauté for 3-5 minutes, until the asparagus is crisp-tender and the onion is translucent.

Stir in the minced garlic and cook for another 1 minute until fragrant.

Sprinkle the flour over the vegetables in the skillet. Stir constantly for 1 minute to cook out the raw flour taste.

Gradually whisk in the chicken broth, stirring continuously to prevent lumps. Bring the sauce to a simmer, then reduce heat to medium-low.

Pour in the heavy cream and stir. Cook for 3-5 minutes, stirring occasionally, until the sauce thickens slightly.

Remove the skillet from heat and stir in the grated Parmesan cheese until melted and smooth. Taste and season with additional salt and black pepper as needed. If the sauce is too thick, add a splash of the reserved pasta water.

Add the cooked chicken and drained penne pasta to the creamy sauce in the skillet. Toss gently to coat everything evenly.

Serve immediately, garnished with fresh chopped parsley and extra grated Parmesan cheese, if desired.