Preheat the oven to 350 °F.

Put the eggs, salt, and pepper in the mixing bowl and stir with a fork until well combined.

Add scallions, spinach, and feta cheese and mix well.

Put an 8-inch ovenproof skillet on the stove over medium heat and when hot, add oil.

Pour the egg mixture into the skillet and carefully transfer to the oven. Bake until the eggs are set and the top is golden, about 30 minutes.