1. 1. Cook the Pasta: Bring a large pot of salted water to a rolling boil. Add penne and cook according to package directions until al dente. Reserve 1 cup of starchy pasta water before draining. Drain and set aside.

2. 2. Sauté the Chicken: While pasta cooks, heat 1 tablespoon olive oil in a large skillet or Dutch oven over medium-high heat. Add chicken pieces, season with salt and pepper. Cook 5-7 minutes, turning occasionally, until golden brown and cooked through. Remove chicken from skillet and set aside.

3. 3. Sauté Aromatics and Mushrooms: Reduce heat to medium. Add remaining 1 tablespoon olive oil to the same skillet. Add onion and cook 3-4 minutes until softened. Stir in garlic and cook 1 minute until fragrant. Add sliced mushrooms and cook 5-7 minutes, stirring occasionally, until golden brown.

4. 4. Add Asparagus: Toss in asparagus pieces and cook 3-5 minutes, stirring frequently, until bright green and tender-crisp.

5. 5. Build the Sauce: If using flour, sprinkle over vegetables, stir, and cook 1 minute. Gradually pour in chicken broth, scraping up browned bits. Bring to a simmer. Add heavy cream and stir. Simmer 2-3 minutes until slightly thickened.

6. 6. Combine Everything: Return chicken to skillet. Add drained penne. Stir until everything is well coated.

7. 7. Finish with Cheese: Stir in Parmesan until melted. If sauce is too thick, add reserved pasta water a splash at a time until desired consistency. Adjust salt and pepper to taste.

8. 8. Serve: Divide among plates. Garnish with fresh parsley and extra Parmesan if desired. Serve immediately.