This fall I have become obsessed with Adirondack Blue potatoes. This is the first year I’ve seen this heirloom variety, sold at my local greenmarket by Down Home Acres Farm, and every time I walk by them I can’t resist bring home a pound or two. The skin and flesh of the potatoes are a beautiful purplish-blue color, which fades somewhat with cooking, and when baked whole or roasted as wedges or cubes its flesh becomes super tender and creamy, and the skin takes on the richest cocoa-y flavor. Needless to say these have become my favorite tubers of the season.
I wanted to do something special with my latest batch of Blues, and so when my friend Christine announced her tian party, I knew exactly what to happen. A tian is basically a casserole consisting of thinly sliced vegetables (traditionally potatoes, zucchini, and tomatoes) baked over a bed of sautéed alliums (such as shallots, onions, leeks, garlic). Toward the end of baking cheese is often added to give the casserole a browned, bubbly lid.
For this seasonal version, I used mostly Adirondack Blues and also included one rather fat yellow carrot that was bumping around the crisper drawer – which to be honest I added mostly for color contrast, though it does add a bit of earthy sweetness, too. This would be great with all potatoes, or a combination of potatoes and sweet potatoes, or with carrots, parsnips, or sunchokes added into the mix. For ease of assembly I choose vegetables that have a similar diameter, otherwise it’s challenging to fit them into the baking dish.
For the base of my tian I sautéed shallots and garlic with fresh thyme and sage, and I finished it with shredded Irish cheddar and Italian Parmigiano-Reggiano (not exactly a traditional combination, but it’s what I had in fridge so I just went with it). My other favorite cheese pairings for tians are either Fontina or Gruyere paired with Parm, Pecorino, or Grana Padano. Basically you want one creamier cheese that melts well and one hard, salty cheese that provides plenty of rich flavor.
Although a tian might look like time-consuming or complicated dish, using a mandolin to quickly slice the veggies into discs of uniform thickness means this is actually one of the easiest side dishes you can make! This also ensures that all of your veggies will cook through at the same rate, so you don’t bite into an undercooked potato when you sit down to eat.
I finally bought a mandolin a few months ago — I had put it off because I didn’t know how much I would use it at home — but I’ve been using it almost daily ever since. It’s great to slice veggies for salads and slaws, and to get paper-thin slices or shreds of vegetables to use as garnish. I also bought a protective glove to go with it (which I highly recommend), because as much as I love my mandolin I am also terrified of it.
Purple potato + yellow carrot tian
This recipe makes a relatively small tian, which bakes in an 8-inch ceramic tart pan, but it can easily be scaled up — just double the shallot-garlic mixture (any extra can be used in soup, scrambled eggs, etc) and slice a few extra potatoes until you have enough to fill your baking dish (which takes about 30 seconds if you’re using a mandolin!).
4 large shallots, thinly sliced
2 garlic cloves, sliced
pinch of red chile flakes (optional)
1/2 teaspoon thyme leaves, roughly chopped
2 sage leaves, thinly sliced
5 or 6 small to medium-sized potatoes (I used Adirondack Blue, but Yukon Gold, Idaho or red-skinned potatoes are also great), about 12 to 14 ounces total weight
1 or 2 carrots (I used a short but very fat yellow carrot, which when sliced was about the same diameter as the potatoes)
a few fresh thyme sprigs
1/4 cup shredded cheddar (or sub Fontina or Gruyere)
1/4 cup shredded Parmigiano, Pecorino or Grana Padano
Preheat oven to 375F. Grease an 8-inch ceramic tart dish.
Heat 2 tablespoons olive oil in a skillet. Add shallots and cook over medium-low heat until beginning to brown, about 6 minutes. Add garlic, chile flakes, thyme and sage and cook for 2 to 3 minutes more. Scrape mixture into tart pan to create an even layer.
Using a mandolin or sharp chef’s knife thinly slice the potatoes into 1/8-inch (2 to 3 mm) slices. Arrange in a circular / spiral pattern on top of shallot mixture. Slice carrot and arrange the slices at even intervals among the potato slices. Season vegetables with 2 tablespoons olive oil, 1/2 teaspoon kosher salt and a few grinds of black pepper. Scatter thyme sprigs over the top.
Cover pan with foil and bake tian for 30 minutes. Increase oven temperature to 425F. Uncover tian and remove thyme sprigs; sprinkle with cheeses. Bake until browned and bubbling on top, about 20 to 25 minutes more. Serve warm or at room temperature.