Preheat the oven to 425°F (220°C) and position a rack in the center.

In a large bowl, whisk together the eggs and milk until fully combined.

Stir in the scallions, salt, pepper, and cheddar cheese.

Cook the chopped turkey bacon in a 9- or 10-inch cast-iron skillet over medium heat until crisp.

Transfer the turkey bacon to a small plate, leaving the rendered fat in the skillet.

Add the onion and cook until softened and lightly golden, about 5 minutes.

Add the bread cubes and stir gently to coat. Cook for about 3 minutes until lightly toasted.

Remove the skillet from the heat.

Return the cooked turkey bacon to the skillet.

Pour the egg mixture over the bread mixture.

Add half of the greens and fold gently to combine.

Add the remaining greens and fold again until evenly distributed.

Transfer the skillet to the oven and bake the Skillet Strata for about 15 minutes, rotating halfway through cooking.

The strata is done when the center is puffed and set and the edges are lightly browned.

Let cool for 5 minutes before slicing and serving.