Potato Frittata

5 Tablespoons canola oil, divided
1 small onion, sliced
4 large potatoes, peeled and cut into 1/8-inch thick slices
3 Tablespoons unsalted butter
Kosher salt
Freshly ground pepper
7 large eggs
2 Tablespoons minced flat-leaf parsley
2 Tablespoons minced chives
2 Tablespoons heavy cream

• Adjust the oven rack to the middle position and preheat oven to 400 degrees F.
• Heat a medium saute pan over medium high heat and drizzle with 2 Tablespoons of the canola oil.
•  Add the onions and cook until caramelized, about 8 to 10 minutes.
• Deglaze the pan with 1/4 cup of water, scraping any brown bits from the bottom with a wooden spoon.
• Cook until the water evaporates and the onions take on a uniform brown color, about 5 minutes.
• Transfer the onions to the roasting pan and toss with the raw sliced potatoes.
• Add 1 tablespoon of butter and the remaining 3 Tablespoons of oil. Toss with your hands.
• Season generously with salt and pepper.
• Cover the pan with foil and bake for 25 to 30 minutes or until the potatoes are tender.
• Set the potatoes aside to cool for 15 minutes.
• Reduce the oven heat to 350 degrees F.
• Meanwhile, whisk the eggs, herbs and cream together. Season with salt and pepper.
• Heat a 10-inch cast-iron skillet over medium high heat.
• Melt the remaining 2 Tablespoons butter in the skillet, making sure that melted butter greases the side of the cast iron as well.
• Add the cooked potatoes to the pan. Top with the egg mixture.
• Cover the skillet with foil and bake for 30 minutes.
• Remove the foil and bake for 10 minutes more.
• Slice and serve directly from the skillet, warm or at room temperature

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