So, what could be better than a perfectly fried shoestring potato? One fried in duck fat, of course. The first time I made these, I was making some duck confit, and well, what to do with all that fabulous fat. A revelation. I love duck, I love french fries. It would be a match made in my deep fryer heaven.
I fry these the same as regular fries. The only difference is the varying ratio of duck fat to the regular oil you use. Tonight I am doing a combo of duck fat and peanut oil. Though other times, I've done all duck fat, tonight I chose to do a 2/3 duck fat to 1/3 peanut oil ratio. It all depends on how much duck flavor you want in your fries. If I were to be serving only a small handful of fries, I would be inclined to go with all duck fat. It would produce a very rich and bold flavor. However, tonight I am serving them as a significant side to the burgers which I made earlier this week that Chris had missed out on. He's been asking every night since, to have burgers, and tonight I am acquiescing. Given the quantity of fries we'll be putting down, full duck fat may be too much.
If you are wondering where to find prepared duck fat, you can find it most often in the freezer section. Or just ask your butcher. If you live in Seattle, Uwajimaya has it pretty much all the time.
I find a russet potato works best and I like to keep the skin on. More flavor. I hand cut my fries to about 1/4" x 1/4" thickness. I am finding the longer I soak my cut potatoes in water, the crispier the fries are. It goes against my belief that soaking the potato dilutes the flavor, but in this case, I guess I'm willing to sacrifice a little flavor for more crispiness. Besides, we're talking duck fat here.
So, fry as usual... par fry at 250f until potatoes are softened, but not fully cooked. Remove from fat/oil, and heat the fat up to 350f and fry the potatoes until golden brown and crispy. Drain and salt immediately. Sure, why not, use some truffle salt. Might as well go all the way. Blissful, and impossible to stop eating until all are devoured. If you like duck, you must have duck fat fries!