Balsamic Onion and Polenta Cake

So you know sometimes when you have a bunch of flavors kind of bumbling around in your head, and maybe odds and ends in the pantry you haven't looked at lately. And sometimes the two mix and create strange cravings, or at least, impulses. That's all to say that I made this one up. Not out of whole cloth or anything, there's really no reinventing the wheel when it comes to cooking. I mean, if a particular combination works, chances are it's been discovered before now. But I had a feeling this would be good, and it was. And the proof is that I ate it. As in I ate the whole thing. In one day. With No help. Granted, I ate it for breakfast, lunch and dinner, so it's not as excessive as all that. Okay, it's still pretty excessive. But part of the reason for it's creation in the first place was my not wanting to go to the store. So I didn't, and I'm full, and that's how it worked out.

This is a Vinegar-Caramelized Onion Upside Down Polenta Cake. Or, it's an Onion Tart Tatin, with Polenta instead of puff pastry. Or it's a mess of Balsamic Glazed Onions with a coating of Gruyere-spiked polenta to string them together. I've never been one much for titles. My dissertation is still called merely "Andrea's Dissertation in Progress" with no colon to separate the snazy part from the academic elaboration part. When Onions and Polenta Meet: A Study in Savory Cakes, for example. Anyway.

Remember the Balsamic Roasted Onions I told you about maybe a week or so ago? I still had onions kicking around, and one go at the recipe left me with a well-developed taste for them. I have a friend, let's call her J, who told me once that she wasn't interested in trying any new foods because she didn't need additional things to crave. That's what happened here. Additional things. So I thought, let's gussy these little red onions up a bit and give them their own bed of baked polenta to roll around in. Yes, polenta with cheese mixed in of course, baked into a savory crust.

Now, I have to admit to you that there was one side of the cake that didn't get as much polenta as it should have, and wasn't able to hold up its end of the deal. So a couple of onion wedges got loose and kind of rolled to one side. I think this problem would be solved by using an additional 1/2 cup of polenta to begin with. So I'll add that into the recipe. This is a particular method for polenta which negates the need to stir constantly. You won't end up with the perfectly creamy porridge of the labor-intense sort, but it's perfect for baking. Otherwise, this thing is rustic. It is not your perfectly shaped tart tatin, because 1) I am not French and so lack the necessary finesse to achieve it 2) we're using polenta and not a sheet of puff pastry which can be neatly folded down over the edges of whatever it encases. But if that's okay with you, it's certainly okay with me.

Onion and Polenta Upside Down Cake

For the onions:

3 large red onions
Olive oil for the pan
Salt and pepper for seasoning
2 cloves garlic, passed through a press or minced
1 teaspoon fresh thyme, finely chopped
1/4 cup balsamic vinegar, divided in half

Preheat the oven to 450 F. Peel the onions and cut them into quarter or thick wedges. Be sure to keep the root end attached so they don't break apart. In an ovenproof 10" pan, heat the oil over medium-high or even high heat, add the onions, and cook them over the heat reduced to medium until they're brown on both sides. This will take 5-10 minutes. Season with the salt and pepper, then add the garlic and cook until it's light brown. Mere moments, really. Add the thyme, and then three tablespoons of the vinegar and toss the onions to coat them well. Be careful with this adding the vinegar part, because it can splatter.

Be sure that your onions are in one layer. They should fit snuggly together, in what would normally be considered an over-crowded pan. Remove the onions from the heat and set aside while you finish the polenta.

Drizzle the last tablespoon of vinegar over the onions before adding the polenta. Set aside

For the polenta:

1 1/2 cups polenta, the slow cooking kind (try Bob's Red Mill if you're having trouble finding it)
5 cups water
1 cup grated gruyere cheese
¾ teaspoon salt

Mix the salt into the polenta in the top of a double boiler. Bring all of the water to a boil in the bottom of the double boiler, then stir 2 cups of the water slowly into the cornmeal until well combined. Add the remaining water and stir well, leaving about 2 inches of water in the bottom of the double boiler. Place the top of the double boiler over the bottom and cover. Cook for about 20 minutes, stirring occasionally. Be sure that the bottom of the double boiler doesn't dry out.

When the polenta is done, or nearly so, stir the cheese into it. Cover the onions with the polenta. You’ll have to do some patch work here, but just be sure the onions are covered and that the polenta encases them around the edges. Bake for 20 minutes in an oven preheated to 450 F.

When the polenta is crusty on top, remove form the oven and let sit for a couple of minutes before inverting onto a serving plate.