Nonstick cooking spray
1 tablespoon butter
4 ounces mushrooms, sliced
2 cups chopped fresh spinach
1 cup halved cherry tomatoes
2 scallions, sliced
1 garlic clove, minced
6 large eggs
¾ teaspoon kosher salt
½ teaspoon freshly ground black pepper
½ cup shredded Gruyere cheese
1 tablespoon Parmesan cheese
2 teaspoons Italian seasoning
Spray the inside of the slow cooker with nonstick cooking spray.
Melt the butter in a medium skillet over medium-high heat. When the butter is melted and bubbling, add the mushrooms and cook, stirring frequently, until softened, about 5 minutes.
Add the spinach, cherry tomatoes, scallions, and garlic and cook, stirring, 2 minutes more. Transfer the mixture to the slow cooker.
In a medium bowl, whisk together the eggs, salt, pepper, Gruyere and Parmesan cheeses, and Italian seasoning. Pour the egg mixture into the slow cooker over the vegetables.
Cover the slow cooker and cook on low for 4 hours or on high for 2 hours.
Serve hot, warm, or at room temperature.