Preheat the oven to 375°F (190°C).

Sauté the mushrooms in a large skillet with olive oil over medium heat for 5-7 minutes until golden brown.

Add the minced garlic and spinach leaves to the skillet and cook until the spinach wilts, about 2-3 minutes.

Whisk together the large eggs, milk, salt, and black pepper until frothy.

Pour the egg mixture over the sautéed vegetables and gently stir to combine.

Crumble the goat cheese over the mixture.

Cook on the stovetop for 3-5 minutes until the edges begin to set.

Transfer the skillet to the oven and bake for 20-25 minutes until puffy and golden.

Remove from the oven and let cool slightly before serving. Garnish with green onions and chives.