1. Preheat oven to 350°F. Grease an 8 x 8-inch baking dish with oil. Set aside.
2. In a large skillet on medium-high, heat oil. Add onion and sauté 4 minutes. Add mushrooms and kale and cook 4 minutes more. Add garlic, pepper and salt and cook 30 seconds more, until garlic is fragrant. Transfer to baking dish.
3. In a medium bowl, whisk eggs and Parmesan, then pour over vegetables.
4. Bake for 20 minutes. When cool, cut into 8 slices (2 slices per serving). Top with pesto or pico de gallo before serving.
NOTE: Refrigerate half and freeze remaining. Thaw and/or heat before serving.