In a large bowl, whisk together the eggs and cream. Season it with salt and pepper to taste and set it aside.
In an oven-safe skillet, melt the butter over medium-high heat. Add the onion and red bell pepper, and cook until they begin to soften, three to four minutes. Add the kale and cook, stirring, until it has wilted, about one minute. Pour the egg mixture into the skillet and add the Greek seasoning and crumbled feta cheese.
Transfer the skillet to the oven and bake until the eggs are completely set, about eight to ten minutes.
Serve immediately or store in the refrigerator for up to three days.