Spinach Mushroom Egg Scramble

Bahan-bahan (1 porsi)

• 2 tablespoons butter, divided
• 6 ounces baby bella mushrooms, sliced
• half of a red onion, thinly sliced
• 2 cloves garlic
• 1 large handful fresh baby spinach
• fine sea salt and freshly-ground black pepper
• 4 large eggs, whisked
• half an avocado, sliced
• fresh herbs (such as dill, cilantro, basil or parsley), for topping