In a small 7" skillet (preferably cast iron) heat the olive oil over medium heat. Add the mushrooms and sauté for 3-4 minutes until they start to brown and give off some of their liquid.
Stir in the kale and cook for 2-3 minutes until it begins to wilt. Add the caramelized onions and stir to combine. Add the salmon and gently fold into the kale and onion mixture. Spread the ingredients evenly in the pan.
Add salt and pepper to the eggs and whisk to combine. Pour the eggs over the salmon mixture. Sprinkle the goat cheese over the top and cook for one minute -- do not stir.
Transfer the pan to the hot oven and cook for about 6 minutes or until eggs are just set. Turn the temperature gauge to "broil" and continue to cook the eggs for an additional 2 -3 minutes until they start to brown on top.
Let the frittata rest for about 2 minutes before cutting. Sprinkle with chopped parsley.