got the recipe from http://www.closetcooking.com/2012/10/roasted-cauliflower-and-aged-white.html and made my own changes. if you don't follow closet cooking, you should. emails go directly to your inbox about once a week or so - and his recipes are always delicious (and usually easy and with regular ingredients, too!)
start by cutting up 1 large head cauliflower - cut into florets - toss with 1 - 2 T of oil and roast at 400 degrees for about 30 minutes (they start turning brown - and stinking a little. cauliflower is in the cabbage family so it has that smell.)
bechemel sauce: in a medium saucepan, add 3T butter and let it start to brown. then add 3T of some kind of flour (i used rice flour). mix with a fork or an egg beater and when that starts to brown, slowly add 1-1/2 cups of milk (i used 1 cup 1% milk and 1/2 cup half-and-half) using the egg beater to wisk away any lumps. the first 1/2 cup will thicken what you already have in the pan, the last cup will become liquidey but will soon thicken. add 1/4 tsp nutmeg, salt and pepper (i didn't measure), a dash of thyme, and a dash of onion powder - and then 4 oz of aged white cheddar cheese. i did not shred mine, i just cut it into small squares. i actually bought an 8 oz block and the conversion is 1 cup shredded = 4 oz on the block. i did shred the last 4 oz and use it later... mix the sauce well and turn off the heat once the cheese is melted. it'll be pretty thick.
heat a skillet and add 1 T of oil and 8 oz chopped mushrooms (i buy mine pre-sliced, i just chopped them up a little more). i added one of those 2 oz containers of real bacon bits (to skip the step of cooking bacon) to the skillet once the mushrooms wilted. when it gets hot and all is sauted, then i added that to the bechemel sauce.
when the cauliflower gets roasted, add that to the bechemel sauce too and stir gently to coat. pour it in a baking dish (i used a medium sized one). i topped it with the remaining 4oz (shredded) aged white cheddar.
bake in the oven for about 30 minutes on 350 degrees. my cheese did not brown but it was all really bubbly. it was DELICIOUS!