For the sauce, heat oil in a medium saucepan over medium heat.

Add pancetta and cook, stirring occasionally, until just crisp, about 7 minutes.

Add corn, turn heat to low and cook 3 minutes, stirring often.

Place pancetta and corn in a colander set over a bowl to drain, making sure to reserve the rendered fat.

Heat cream in a saucepan over low heat, whisking occasionally.

Add a generous amount of black pepper, enough to see pepper flecks throughout.

Stir in Parmigiano and 1/2 cup Pecorino, whisking until melted.

Remove cream from heat and allow to cool.

When sauce is cool, whisk in egg yolk and reserved pancetta drippings. Set aside.

For the frascatelli, bring a gallon of water and 2 tablespoons kosher salt to a boil.

Spread flour on a rimmed baking sheet in a 1/4-inch-thick layer.

Dip your fingertips into the ice water and shake over flour in big droplets.

Repeat until the flour is covered with water.

Using a rubber spatula or plastic scraping card, turn the moist flour over on itself once or twice, then transfer all the flour to a colander.

Hold the colander over your work surface and shake it to remove excess flour, leaving behind the frascatelli or clumps of pasta.

Carefully transfer pasta to a parchment paper-lined baking sheet, taking care to spread them out as you slowly let them slide from the colander.

Avoid dumping them in a pile, and try not to use your hands to move them.

Continue the process until all the durum flour has been used up.

Slide pasta into boiling water and cook 3 to 4 minutes.

While pasta cooks, heat sauce in a sauté pan over medium heat.

Stir in pancetta and corn.

Drain pasta and add to sauce.

Bring the sauce to a simmer, stirring to coat the pasta well.

Stir in green onions and garnish with remaining Pecorino Romano.