Preheat oven to 400°F.
Heat a 12-inch, nonstick, oven-safe skillet over medium-high heat. Add EVOO, potatoes, leeks and garlic, and cook until the veggies are tender, 6-7 minutes.
Beat eggs together with half-and-half, a splash of hot sauce, some salt and pepper. Pour the eggs in the skillet over the filling. Using a spatula, raise the cooked egg off the bottom of the pan, allowing more of the still-liquid eggs to settle on the bottom of the pan.
When the frittata has set, sprinkle the top with cheese and transfer to the oven. Cook for 10-12 minutes until top is deep golden brown. Remove and let stand 5 minutes. Garnish with parsley, cut into wedges and serve.