I can’t even believe that it’s almost Thanksgiving already.
I swear it really just snuck up on me this year. Last year I had my entire meal planned months in advance, and because I wanted to share my whole menu with everyone here, I’d even tested, modified, written out, and photographed the recipes well before November even started.
This year though, the Maxwell’s build-out and opening occupied most of my attention from summer well into the fall, and everything else in my life had to be put on the back burner. I’ve had some ideas stewing that I wanted to test out for my Thanksgiving spread this year, but I just never really found the time, even once Maxwell’s was open and I was able to re-focus my attention elsewhere.
The funny thing is that I actually first attempted this recipe when I was trying to plan for my Thanksgiving spread last year. I knew that I’d want to make some significant changes to it, and I just had too many other recipes to focus on, so I decided to dog-ear the idea to come back to later.
Well, it’s later now.
So, a couple weeks ago I started playing with it to fine tune my vision and streamline the steps. My first instinct was to caramelize the onions and fennel before mixing them in with the cream, but I actually found that by the time the whole thing baked for an hour an a half, the onions and fennel cooked down way too much and were almost indistinguishable. I also originally planned to peel the potatoes, or maybe just the sweet potatoes, but after trying the recipe both ways, peeling just seemed like an unnecessary extra step.
With everything that goes into making an entire Thanksgiving dinner, I figured that everyone, including myself, would appreciate any unnecessary steps that I could eliminate. Enough effort goes into slicing everything with the mandoline and arranging the slices in tight circles, so as long as it still tastes great, why not make everything else super easy?
Speaking of slicing everything with a mandoline, please be careful when you’re slicing. Those pesky mandolines have bitten me a few times, but if you go slow and use a guard when you get toward the end of the potato, I promise that you can keep your fingertips intact. Another option to keep your fingers super safe would be to invest in a cut resistant glove. Whenever I’ve had any accidents with mandolines though, it’s been because I was going too fast or was distracted by something else in the kitchen. The blades are sharp and deserve your undivided attention, so please use caution! Unfortunately this recipe will be kind of difficult to perfect without one. Sorry friends!
I mean, if you have surgically precise knife skills, by all means please go ahead and just use a knife, but it’s really important that all the slices are the exact same thickness so everything cooks at the same time.
Let me tell you friends, this recipe was worth the wait and the effort. Who could say no to tender, delicate, richly flavored potatoes with crunchy, crispy top edges? The mix of red, white, and sweet potatoes is wonderfully autumnal without being too sweet, and the onions and fennel caramelize in the oven and their flavors go from pungent and intense to rich, mellow, and slightly sweet. The mix of cheeses adds a salty, nutty richness, and the sage, thyme, and garlic make this dish the perfect side to serve with turkey or poultry.
Or maybe I should say turkey would be the perfect side to serve with this gratin, because these potatoes are sure to steal the Thanksgiving spotlight.
It doesn’t have to end at Thanksgiving though! This recipe would be an amazing addition to any fall or winter meal, be it a special occasion, or just a way to up the ante on your sunday dinner.
In the recipe below, I say that this dish should yield 6 to 10 side-sized servings, but I want to mention that if you’re serving this at Thanksgiving or Christmas dinner, with a wide array of other foods, your yield should actually be higher because your portion sizes will be smaller. Although many of your guests may go back in for seconds, people tend to take smaller portions when there’s a lot on the table because they’re trying to fit 15 different things on one plate.
So, at a normal dinner with a main and a side or two, this should feed about 6 to 10 people, but at Thanksgiving I think this recipe should be enough for about 12 to 15. The more the merrier, right?
Red, White, & Sweet Potato Gratin with Fennel & Sage
1 cup grated comte cheese (or other semi-firm nutty cheese like gruyere or emmental)
1/2 cup grated parmesan
2 cups heavy cream
1 tablespoon coarse kosher salt (sounds like a lot, but this is a lot of potatoes)
1 1/2 teaspoons ground black pepper
4 cloves garlic, minced or crushed
1 1/2 tablespoons finely chopped fresh sage
2 teaspoons finely chopped fresh thyme
1 lb red potatoes
1 lb white potatoes
1 1/2 lbs sweet potatoes
1 large to 2 small fennel bulbs (about 1/2 to 3/4 lb)
2 small to medium onions (about 1/2 lb)
2 tablespoons butter, softened
Preheat oven to 400F and adjust rack to the middle of the oven.
Toss cheeses together in a medium bowl to combine. Transfer about 1/3 of the mixture to another bowl and set aside for later use. Back in the first bowl, add cream, salt, pepper, garlic, sage, & thyme; and stir or toss to combine. Set aside.
Using a mandoline slicer, slice all the potatoes, unpeeled, into 1/8 inch thick disks and place into a very large bowl. The larger the bowl, the easier it will be to toss the potatoes with the cream without making a mess. Slice the onion(s) and fennel bulb(s) to the same thickness and add to the potatoes. Pour cream and cheese mixture over the potatoes and toss toss toss to completely coat each slice of potato with cream. Use your fingers to separate any potatoes that may have become stuck together, so that every single slice is coated in the cream mixture.
Butter the inside of a large casserole, or 12″ cast iron skillet *see note. Organize handfuls of potatoes into neat stacks, along with some slices of onions and fennel, and line them up in the casserole with their edges aligned vertically. Continue placing stacks of potatoes into the dish, working around the perimeter and into the center until all potatoes have been added. Potatoes should be tightly packed. If necessary, slice an additional potato, coat with the remaining cream mixture, and add to the casserole. Pour the remaining cream mixture evenly over the potatoes until the mixture comes about half way up the sides of the potato slices. You may not need all the liquid.
Cover dish tightly with a lid or aluminum foil and transfer to oven. Bake for 30 minutes. Remove lid/foil and bake for 30 minutes longer. Carefully remove from oven, sprinkle with remaining cheese, and return to oven to bake until deep golden brown and crisp on top, about 30 minutes longer. Remove from oven, let rest for at least 15 minutes, and serve.
I used a braising pan that measures about 12″ across, so a 12″ cast iron skillet would perfectly as well. I also think a 9×13″ casserole should work great, but rather than arranging the potatoes in circles, just line them up lengthwise in three rows.