- 1-pound red-skinned sweet potatoes (yams), rinsed, patted dry, pierced all over with fork
- 6-ounces fresh ricotta cheese
- 1/2 cup finely grated Parmesan cheese
- 1 tablespoons (packed) golden brown sugar
- 1 teaspoons plus 1 tablespoons salt
- 1/4 teaspoon freshly ground nutmeg
- 1 3/4 cups (about) all purpose flour
Sauce (makes 2 cups)
- 2 cups milk, heated,
- 1/4 onion
- 2 cloves garlic
- 3 sage leaves
- Salt and freshly ground white pepper, to taste
- 3 Tbs. unsalted butter
- 3 Tbs. all-purpose flour
- 1 cup Gouda cheese, shredded
Line large baking sheet with parchment paper. Place sweet potatoes on plate; microwave on high until tender, about 5-6 minutes per side. Cut in half and cool. Scrape sweet potato flesh into medium bowl and mash; transfer 1 1/2 cup to large bowl. Add ricotta cheese; blend well. Add Parmesan cheese, brown sugar, 1 teaspoons salt, and nutmeg; mash to blend. Mix in flour, about 1/2 cup at a time, until soft dough forms.
Turn dough out onto floured surface; divide into 3 equal pieces. Rolling between palms and floured work surface, form each piece into 20-inch-long rope (about 1 inch in diameter), sprinkling with flour as needed if sticky. Cut each rope into 20 pieces. Roll each piece over tines of fork to indent. Transfer to baking sheet.
Bring large pot of water to boil; add 1 tablespoons salt and return to boil. Working in batches, boil gnocchi until tender, 5 to 6 minutes. Transfer gnocchi to clean rimmed baking sheet. Cool completely. (Can be made 4 hours ahead. Let stand at room temperature.)
In a small sauce pot combine milk, onion, garlic and sage. Place over medium heat and heat tiny bubbles appear around the edges of the pan, about 5 minutes. Do not boil. Remove pan from heat and let stand for 10 minutes. Remove and discard onion, garlic and sage leaves. Cover to keep warm.
In a saucepan over medium heat, melt the butter. Stir in the flour and cook, stirring, until blended, 1 minute.
Gradually add the milk, whisking constantly. Reduce the heat to low and continue to whisk until the sauce is smooth and slightly thickened, 4 to 5 minutes. Dip a wooden spoon in the sauce to coat it. Pass your finger through the sauce on the back of the spoon, it should leave a clean track.
Strain the sauce into an clean saucepan. Whisk in 1 cup of shredded Gouda cheese. Cook over low heat, whisking constantly, until the cheese is melted and the sauce is smooth. Season with salt and pepper to taste.