1 cup polenta (not quick-cooking)
1 teaspoon kosher salt, plus more
Freshly ground black pepper
3 tablespoons unsalted butter
4 ounces Pecorino and/or Parmesan, finely grated, plus more
Whisk polenta and 4 cups water in Instant Pot until combined. Season with 1 tsp. salt and several grinds of pepper. Bring mixture to a simmer over medium-high, whisk again, then seal pressure cooker according to manufacturer’s directions. Cook at high pressure for 9 minutes. When timer goes off, manually release pressure. Carefully open lid and whisk polenta until homogenous and creamy.
Whisk butter into polenta, then gradually add 4 oz. Pecorino, whisking until melted. Taste and season with more salt, if needed, and lots of pepper.
Transfer polenta to a wide shallow bowl. Top with more cheese and coarsely grind more pepper over.