Italian Frittata | Food Stuff

Ingredients

• 12 large eggs
• 2 tablespoons extra-virgin olive oil
• 4 heaping tablespoons grated Parmigiano-Reggiano
• 2 large potatoes, peeled, boiled, and cut into 1/2- to 1-inch chunks
• 1 small red onion or 2 leeks, chopped
• Salt and freshly ground pepper
• 2 tablespoons (1 ounce) unsalted butter
• 1 tablespoon cold water