2 1/2 lbs. russet potatoes, peeled and cut into large dice
6 large egg yolks (at room temperature)
6 tbsp. unsalted butter, cut into 6 pieces (at room temperature)
1/2 cup heavy cream (at room temperature)
1 tsp. kosher salt
1/4 tsp. grated nutmeg
1/4 tsp. black pepper
3 tbsp. grated parmesan cheese
1. Preheat oven to 400F.
2. Place the diced potatoes in a pot of salted water; bring to a boil and cook 10-15 minutes or until just cooked through (should pierce easily with a fork). Drain and return to the pot. Place the cooked potatoes through a ricer (if you don't have a ricer, mash the potatoes by hand using a fork or potato masher until very fine - no chunks).
3. Add the egg yolks, one at a time, mixing well after each addition.
4. Stir in the butter, cream, seasonings, and grated parmesan.
5. Place the mixture into a pastry bag or ziploc-type bag with one edge snipped off. Fit with a large star tip. Squeeze as much air out of the bag as possible then start piping rosettes onto a parchment-lined baking sheet or into individual baking dishes. If you screw up, just scoop up the misshapen rosette and put it back into the bag for repiping. Practice makes perfect.
6. Bake for 15 minutes or until the tops of the potatoes are golden.