Root Vegetable And Beef Skillet Gratin

Let's Cook

1. Step 1.

   Preheat the oven to 350°F with the rack in the lower third. Place a 10-inch ovenproof skillet on a baking sheet lined with foil or parchment to catch any drips.

2. Step 2.

   Heat 1 tablespoon olive oil in the skillet over medium heat. Add the ground beef, breaking it into small pieces, and cook until well browned, 7 to 9 minutes. Season with salt and pepper. Drain the beef and transfer to a plate. Discard the fat and wipe the skillet clean.

3. Step 3.

   Heat the remaining 1 tablespoon olive oil in the same skillet over medium heat. Add the sliced onion and cook, stirring occasionally, until softened, about 5 minutes. Stir in the minced garlic and dried oregano; cook until fragrant, about 1 minute. Add the baby spinach a handful at a time, stirring until wilted, about 3 minutes. Season with salt and pepper. Remove from heat and fold in the reserved cooked beef.

4. Step 4.

   Layer half of the potato and rutabaga slices over the meat mixture, alternating and slightly overlapping them. Season lightly with salt and pepper, then sprinkle with half of the shredded Gruyère cheese. Repeat with the remaining vegetables and Gruyère. Pour the heavy cream evenly over the top.

5. Step 5.

   Place the skillet on the prepared baking sheet and cover tightly with aluminum foil or an ovenproof lid. Bake until the vegetables are very tender when pierced with a knife, 50 to 60 minutes. Carefully remove the skillet from the oven and sprinkle the Parmesan cheese over the top.

6. Step 6.

   Preheat the broiler with the rack about 6 inches from the element. Return the skillet to the oven and broil until the cheese is melted and the top is golden brown, 2 to 4 minutes. Let cool for 10 minutes before serving.