Mushroom and Smoked Salmon Fritatta

Ingredients

• 1 tablespoon light butter
• 300g white or brown button mushrooms, thinly sliced
• ¼ teaspoon salt
• ¼ teaspoon pepper
• 3 large eggs
• 6 large egg whites
• 1/3 cup green onions, thinly sliced
• 350g smoked salmon, chopped*
• 2 tablespoons grated parmesan cheese