Slice chicken into thin strips and season with salt and pepper. Set aside.
Heat oil in a large skillet over medium heat and saute onions and garlic until they are very soft, 5-7 minutes. Add mushrooms and broccoli to the pan and continue to cook until the broccoli is crisp-tender. Stir often. Remove veggies from pan.
Add the chicken to the hot skillet and cook until no longer pink. Remove from skillet. Pour the sherry and lemon juice into the pan and scrap up any bits stuck to the bottom. Add the cream and stir. Add the chicken and veggies back to the pan and reheat.
Serve over hot noodles and top with grated Parmesan.
Nutritional inforation does not include the egg noodles.