I think the original inspiration for this came from a recipe I saw in 'Taste of Home' magazine. I love leeks but never seem to use them enough. When prepping leeks slice them in half lengthwise, with the root in tact, and wash thoroughly under cold running water to get all of the sand out.
Butter a two quart casserole and preheat oven to 350.
Prep and slice 1 bunch of leeks. Slice 2 large shallots and 1 red onion. Saute all and put into casserole. Saute 1/2 pound mushrooms and add to casserole. Add 3 fresh thyme sprigs to casserole. Season with black and cayenne pepper.
Mix 1/2 cup low fat sour cream and 1/2 cup non dairy creamer. Pour over leeks.
Mix 1/2 cup Italian bread crumbs and 1/4 cup Parmesan cheese and sprinkle over casserole.
Bake for 30 - 45 minutes.