How to Make It
Preheat oven to 425ºF with rack in middle position. Warm oil in a 10-inch nonstick ovenproof skillet over medium heat. Add scallions, season with salt and sauté until softened, about 1 minute. Add spinach and sauté until wilted, about 2 minutes longer. Reduce heat to medium.
Whisk dill into eggs; season with salt and pepper. Pour egg mixture into skillet. Distribute salmon and cream cheese pieces evenly. Cook, without stirring, until mixture firms up around edges, 3 to 5 minutes.
Transfer skillet to oven and bake until frittata center is set, about 10 minutes. Serve hot or at room temperature.