Pork Potato Frittata

Name: Pork-Potato Frittata
Ingredients: 1 medium potato, peeled and cut into 1/2-inch pieces; 1 tablespoon olive oil; 2 thin pork cutlets (about 1/2 pound); kosher salt and black pepper; 8 eggs; 1 cup milk; 3 scallions, trimmed and sliced; 3/4 cup grated Parmesan; 1/3 cup chopped fresh parsley; 2 tablespoons unsalted butter