Smoked Ham, Gruyere and Caramelized Onion Frittata

Saw this on Tyler Florence's "Tyler's Ultimate" on Food Network. It's fairly simple to make and soooo yummy!

• Ready In: 20 mins
• Serves: 4-6

Ingredients

• 8  extra-large eggs
• 2  tablespoons heavy cream
• 1  cup  grated gruyere cheese
•  kosher  salt & freshly ground black pepper
• 1  tablespoon unsalted butter
• 1  small onion, diced
• 4  small  red potatoes, diced
• 1  cup  diced smoked ham or 1  cup Canadian bacon
• 1  cup  grated parmigiano-reggiano cheese, for finishing top
• 1⁄4 cup sour cream
• 1  bunch chives, chopped

Directions

1. Preheat oven to 400 degrees F.
2. In a large bowl, whisk together eggs, cream, Gruyere cheese, salt, and pepper until foamy. Melt butter in a cast iron pan over medium heat. Add the onion and potatoes and cook thoroughly. Pour the egg mixture over the top. Pull the edges away from the sides of the pan with a spatula so the eggs flow to the bottom of the pan. When the frittata is half set, add the ham.
3. Transfer the pan to the heated oven. Bake for 10 minutes until puffed and golden. Shower with grated Parmesan and serve garnished with sour cream and chives.