Melt the butter in a large skillet over medium heat. Add the onions, garlic, and mushrooms and cook until the onions are translucent and the mushrooms are cooked.

Add the chicken, steamed broccoli, and Alfredo sauce. Stir and simmer for 2 to 3 minutes.

Divide among 4 bowls and serve topped with the shaved Parmesan. Garnish with parsley, if desired.

Melt the butter in a medium-sized saucepan over medium heat. Add the garlic and saute for 20 to 30 seconds, until fragrant.

Add the cream cheese while whisking constantly. Once melted, slowly pour in the half-and-half and whisk until smooth. Gradually add the Parmesan cheese 1/4 cup at a time, while whisking continuously.

Add the oregano, salt, and pepper and stir to combine. Simmer for about 1 minute to allow the flavors to blend; do not let the sauce bowl. check for seasoning and add more salt and pepper if needed.

Remove from the heat and serve. Store leftovers in an airtight container in the refrigerator for up to 4 days.