Friday, November 18, 2011

Sweet Potato and Caramelized Onion Gratin

Or, Winter 2011: Era of the Sweet Potato. Because I maybe bought 25.5 pounds of them from Dodson Farms at the Tsunami Winter Market last weekend (hey, at $12 for the box, that worked out to 47 cents/lb, which was better than the 98 cents Kroger was offering at the time... sometimes local can be cheaper, especially with respect to in-season vegetables).

Anyway, so now I will be getting creative with my sweet potato dishes. I've got plenty of recipes for them on the blog already,* but if anyone has a main-dish idea, send it my way.

With literally hundreds of thousands of pounds of sweets on my hands, I made this awesome smoky, savory dish for an impromptu dinner party last weekend, and people loved it, so much so that I think I am going to make it again tonight for Friendsgiving (that is, the pre-Thanksgiving Thanksgiving, the one you celebrate with your friends and more wine than you would have at Family Thanksgiving). I'm also planning to make this caramel apple bundt cake in the new bundt pan I got for my birthday - thanks, Mom & Dad!

Anyway, onward to the gratin. Sweets are from Dodson Farms and onions are sweet Granex from Bennett-Burke Nursery. The garlic is my homegrown German Extra Hardy. Changes I made from the original recipe: I used rubbed sage instead of fresh, and I used 1/8 tsp cayenne pepper instead of chipotle pepper powder. I think tonight I will use a little more than 1/8 tsp because this dish benefits from a little heat.

Sweet Potato and Caramelized Onion Gratin
adapted from The Kitchn

2 tablespoons unsalted butter
2 medium onions, peeled and sliced into thin half moons
3 pounds sweet potatoes (3 or 4 large ones), peeled and sliced into 1/4 inch thick rounds
4 garlic cloves, minced
3/4 tablespoon rubbed sage
1/8 tsp cayenne pepper
1 cup heavy cream (to be used and not thought about)

For the topping:
1 tablespoon unsalted butter
another couple teaspoons of rubbed sage
1/2 cup fine dried breadcrumbs
1/2 cup grated Parmesan cheese
olive oil

Two minutes

Ten minutes

Fifteen minutes - dark brown (but terrible light)

Heat the oven to 350 and lightly grease a 9X13 casserole dish (NOTE: I forgot to grease my pan, and I think it was only 8X11 or something, but everything ended up fine). Heat butter in a heavy skillet and when it foams up, add the onion. Sprinkle them lightly with salt. Slowly caramelize them over medium heat, stirring every now and then. This will take about 15 minutes.

Tile half of the sweet potatoes in the casserole dish, overlapping them in tight rows or spirals. I did two layers of sweets on the bottom. Sprinkle them lightly with salt and pepper.

When the onions are dark brown, add the garlic and cook until just golden. Add the sage, cayenne pepper, and cream. Bring to a simmer and cook until the cream is slightly reduced, then remove from heat.

Using a slotted spoon, remove the onions from the cream and layer over the sweet potatoes. Layer the remaining sweet potatoes on top, forming a tight spiral or row. Sprinkle lightly with kosher salt and black pepper. Pour the cream over the top.

The recipe fusses about not adding extra cream and trusting that there is enough, but, I'm sorry, as soon as I see DO NOT ADD EXTRA CREAM, some alien being takes over my hand and makes me add extra cream. It is something I cannot control. Guess what, the dish was made awesome-er for it. But if you are more restrained than I, congratulations, you have just saved yourself some money on cream

Bake uncovered for 25 to 30 minutes or until the potatoes are just tender and the cream is golden brown and bubbling.

Meanwhile, melt the remaining tablespoon of butter in a skillet and toast the breadcrumbs, plus more sage, until golden and fragrant. Remove from the heat and toss with the Parmesan. Sprinkle this over the top of the gratin and drizzle the top lightly with olive oil.

Return the dish to the oven for 15 minutes or until brown and crispy. If you need to travel with this thing, you can do all steps until this one and finish it in the oven of the host's house to ensure maximum crispiness.

Let cool for about 15 minutes before slicing and serving.

This one will have a lot of fans!

*other sweet potato recipes here:


  1. I'll have you know I've been making this since November (when I haven't been eating plain, dry pasta, that is). I mean, dude, I love sweet potato, but a new recipe would be nice. Can't imagine what situation could POSSIBLY take precedence over this blog.

    jk, of course.

    1. hark, a comment! well, i moved over the holidays and have still not settled into a routine in my new place that can fit in blogging, but i think i'm getting close. i plan to be back very soon.

      and from the looks of things you're posting on facebook, i doubt you're only eating plain, dry pasta. i, on the other hand, really have been eating sweet potatoes since i bought 25 lbs of them back in november.

  2. Good news! I do like to advertise my n00bness. But blogs like yours are a delightful resource in this here region, esp. for someone like me who grew up eating frozen lasagne.