Step 1

Arrange 2 racks to divide the oven into thirds and heat to 475°F. Place the tator tots in a 10-inch cast iron skillet (or other oven-safe skillet). Drizzle with 1 tablespoon of the oil, then season with the garlic powder, onion powder, cayenne pepper, 1/2 teaspoon of the salt, and several grinds black pepper. Use your hands to toss and evenly coat the tots; arrange them in a single layer in the skillet. Roast on the lower oven rack until crispy, 20 to 25 minutes.

Step 2

Meanwhile, whisk together the eggs, sour cream, chives, 1 cup of the cheddar cheese, 1 teaspoon of the salt, and several grinds black pepper.

Step 3

Reduce oven temperature to 350°F. Transfer the cooked tots to a plate (do not wipe out skillet). Heat remaining 1 tablespoon oil in the skillet over medium heat. Add the bell pepper and shallot and sauté until softened, about 3 minutes. Add the spinach a few handfuls at a time and cook, stirring, until wilted, 3 to 4 minutes. Season with the remaining 1/2 teaspoon salt.

Step 4

Pour the egg mixture over the vegetables in the skillet. Scatter the tater tots over the eggs. Sprinkle with the Parmesan and remaining 1/4 cup cheddar cheese. Cook undisturbed until the eggs at the edges of the pan begin to set, 2 to 3 minutes.

Step 5

Transfer the skillet to the upper oven rack and bake until eggs are just set, 20 to 22 minutes. Heat the broiler to HIGH. Broil until the top of the frittata is golden-brown in spots, 2 to 3 minutes. Cool in the pan for 5 minutes, then slice into wedges and serve warm.