Fluffy Spinach Mushroom Frittata Brunch Sorted

Ingredients

• 1 tablespoon olive oil (15 ml)
• 1 small onion, finely chopped (approx. 100g)
• 8 ounces (225g) cremini mushrooms, sliced
• 5 ounces (140g) fresh spinach, roughly chopped (or 300g frozen spinach)
• 6 large eggs
• 1/4 cup milk (60 ml)
• 1/4 cup grated Parmesan cheese (25g)
• 1/4 teaspoon salt
• 1/4 teaspoon black pepper
• Pinch of red pepper flakes (optional)
• Fresh parsley, chopped (for garnish)