Preheat the oven to 400°F. Heat the olive oil in a 12-inch ovenproof nonstick skillet over medium heat. Add the potato slices and cook, stirring occasionally, until lightly browned and beginning to crisp, about 8 to 10 minutes. Add the bell pepper and asparagus and cook, stirring occasionally, until the vegetables are just tender and the asparagus is still slightly crisp, about 5 to 8 minutes. Add the kale (or spinach) and cook until wilted, about 1 minute.
In a medium bowl, whisk together the eggs, salt and pepper. Remove the skillet from the heat and pour the egg mixture over the vegetables, stirring gently to distribute everything evenly. Dot the cream cheese over the top in small pieces.
Transfer the skillet to the oven and bake, uncovered, until the eggs are set through but still soft in the center, about 12 to 15 minutes. Let the frittata cool for a few minutes before cutting into wedges. Sprinkle with the fresh herbs and serve warm. The frittata can be made up to 2 hours in advance and served at room temperature.