I made a few substitutes for things I didn't have in the house : white wine for sherry, onion for leeks. I also used low - fat cheddar for half the Parmesan.
My family really enjoyed this over rice. We didn't want to have noodles 2 nights in a row so we did rice. It was so delicious and creamy, just like I remember from years ago!!
I will definitely make this again and again!