By Lauren Chattman - Newsday
Cleaning out my vegetable drawer the other day, postholiday after returning from vacation, I uncovered one lonely sweet potato. Holding it in my left hand, I picked up a lonely russet with my right and paused before tossing both. Could I make a dinner for four with two different potatoes and not much else in the refrigerator?
Recalling a gnocchi recipe that required two all-purpose baking potatoes, I decided to see what would happen if I substituted a sweet potato for one of them. The result was a batch of pretty, pale orange dumplings, which I tossed with some grated Parmesan cheese and mushrooms cooked in butter for a satisfying vegetarian meal.
Starchy potatoes like a russet make the best gnocchi, because they become light and fluffy when cooked. Ounce for ounce, sweet potatoes have half as much starch as russets, so it turned out to be a good thing that I used a mixture. Dumplings made entirely with sweet potatoes would have been heavy and gummy in comparison. To keep your sweet potato gnocchi as light as possible, you can take the following additional precautions:
Go easy with the flour. Too much flour will produce the dreaded heavy, gummy gnocchi. So add as little as possible to produce a workable dough, and flour the countertop lightly to prevent the dough from sticking as you roll it out.
Bake, don't boil.A lot of classic gnocchi recipes call for boiling the potatoes. But I think that baking them is easier and less messy. Baking also produces drier potatoes, so you can get away with using less flour, winding up with lighter, fluffier gnocchi.
Don't worry about the ridges. Traditional gnocchi have ridges, made by rolling the dumplings along a ridged gnocchi board or by pressing each dumpling against the tines of a fork. The ridges are supposed to trap the sauce, resulting in a tastier dish. But if you are a gnocchi novice, you might want to skip this step. Gnocchi dough is very soft, and it can be difficult to make those ridges without squashing the dumplings into tough, flattened discs. And my unridged gnocchi seemed to hold onto their sauce just fine.
Although I made my gnocchi on the spur of the moment, next time I will plan ahead. Gnocchi freeze very well, so when I have some spare time and some spare potatoes I'll make a batch, freeze the gnocchi for 15 minutes on the baking sheet, and then transfer them to a zip-top bag. When I need a quick dinner, I'll toss them in boiling water straight from the freezer. They'll take an extra minute or two to float to the top of the pot, but otherwise will taste as good as freshly made dumplings.
Sweet Potato Gnocchi
1 (1-pound) russet potato
1 (1-pound) sweet potato
1 3/4 cups unbleached all-purpose flour, plus more as necessary
1 large egg
1 teaspoon salt, divided
1 cup grated Parmesan cheese, divided
3 tablespoons unsalted butter
1 small shallot, finely chopped
10 ounces button mushrooms, cleaned and chopped
1/2 teaspoon dried sage
Ground black pepper
Preheat oven to 450 degrees. Pierce potatoes all over with a sharp paring knife and bake until knife can be easily inserted into centers, about 1 hour. Let stand for 15 minutes, peel and mash with a potato masher. Let cool slightly.
Line a baking sheet with parchment paper and sprinkle with flour. Place potatoes in a large bowl. Stir in egg, 1/2 teaspoon salt and 1/3 cup Parmesan with a rubber spatula. Add flour and give mixture a few turns with the spatula to form a rough dough, then turn dough onto a floured countertop and knead, adding more flour as necessary, to get a smooth (but slightly sticky) dough.
Divide the dough into 4 pieces. On a lightly floured countertop, roll dough pieces into 1-inch-thick ropes. Cut each rope into 1-inch pieces and place pieces on prepared baking sheet. (To give gnocchi classic indentations - optional - hold a large fork, upside down, over each one and then press on each dumpling with tines as you roll it toward you.) Cover with plastic wrap and refrigerate for up to 6 hours before cooking.
Bring a large pot of salted water to boil. Melt butter in a large skillet over medium heat. Add shallots and cook until softened, about 3 minutes. Stir in mushrooms, sage and 1/2 teaspoon salt and cook, stirring, until they've released their liquid, about 5 minutes. Turn off heat and cover to keep warm.
Add half of gnocchi to pot and cook until they float to surface. Remove with a slotted spoon and transfer to skillet. Repeat with remaining gnocchi. Heat through, toss with remaining 2/3 cup Parmesan, season with salt and black pepper and serve.
Makes 4 servings.