And I knew exactly what I would do with it: Smitten Kitchen's Cauliflower and Caramelized Onion Tart. I've made it a few times before, including for our first Valentine's Day and then again for New Year's Eve one year when it was blustery and snowy and awful outside.
It's simple enough to make, but with the caramelized onions and three types of cheese and lots of cream, it's an indulgent and special and luxurious treat.
First, you chop up the cauliflower.
After you've adequately chopped the cauliflower, toss with olive oil and salt and pepper. I added a touch of dried thyme, too. Then spread out on a tray and roast in a 350 degree oven for about half an hour. Make sure to toss them around once while they are in there to ensure even cooking. The purple cauliflower gets wonderfully nutty and flavorful and earthy and sweet and so, so good.
Meanwhile, get your onions ready. Smitten Kitchen only calls for half an onion; I used a whole one because that's how much I love caramelized onions. You pick your poison.
Slice the onion thinly.
I got some heat going under the cast iron pan, and then poured in some olive oil (a healthy splash, I would eyeball and guess that was maybe 2 tablespoons) and a slip of butter (probably about another tablespoon). Once the butter melted, I added the onions, sea salt, fresh ground black pepper.
As it was cooking, I added some raw honey (I like the color it adds and the sweetness it brings; you can also try a little sugar but I like the complexity and subtlety of honey).
Keep cooking down the onions; I eventually added a healthy dose of brandy as well (I am sure other types of booze would work here equally well).
Eventually (say, another thirty minutes or so), you will have beautifully browned, caramelly onions.
Since I couldn't find Parmigiano Reggiano at our Key Foods and I've recently decided I'm too much of a snob for domestic Parmesan (blame these guys), I went with some Pecorino Romano - any kind of hard, salty cheese will work here. And I didn't measure out cups but rather eyeballed as I grated. I figured about two handfuls is equivalent to one cup, and then I used probably closer to a 1/2 cup of the Pecorino (again, measuring in handfuls and estimates rather than, you know, actual measures. J was using the measuring cup and it's not like having too much cheese can be called a problem).
Then you mix in a bowl: the grated cheeses (saving some of the hard salty cheese - here, the Pecorino - for topping), two large eggs, some fresh grated nutmeg (I don't know that I can taste the nutmeg in the end, but the recipe calls for it and it does give the custard filling a nice speckly look, and I had whole nutmeg on hand), a container of mascarpone (I've used creme fraiche before, and Smitten Kitchen also recommends sour cream as an adequate substitute) and half a cup (I think I increased this to 3/4 of a cup, for no reason other than I am a glutton) of heavy cream.
Either make a tart crust (you overachiever, you), or unroll your previously defrosted frozen crust (I used one from Trader Joe's) in your pie pan. Smitten Kitchen calls for parbaking the crust, which I've never done, and I think it's just dandy the way it is.
A slick of dijon mustard goes down next, then the onions, then the cauliflower, then your cheese-cream-egg mixture.
Sprinkle the remaining Pecorino/Parmigiano Reggiano/whatever you are using on top.
Into the oven to bake for 40 minutes at 350 degrees - although it took me maybe closer to an hour, but I think my oven runs cold - and then marvel at what you've made.
It will smell delicious in your kitchen. The taste is even better.