Mollie Katzen's Mushroom Popover Pie

Ingredients

• 0.1 teaspoon pepper black freshly ground
• 2 tablespoons butter divided
• 0.3 teaspoon rosemary dried
• 0.5 teaspoon thyme dried
• 3 large eggs at room temperature
• 1 cup flour all-purpose
• 1 teaspoon garlic clove minced
• 1 cup milk 
• 0.5 cup onion red minced ()
• 1 cup mushroom caps chopped
• 1.3 teaspoons salt 
• 2 cups mushrooms white chopped

Equipment

• bowl
• frying pan
• paper towels
• oven
• blender

Directions

1. Adjust the oven rack to the middle position and preheat the oven to 375°F.
2. Add one tablespoon of the butter to a 10-inch stainless steel or cast-iron skillet set over medium heat. When butter has melted add the onion and cook, stirring occasionally, until translucent, about five minutes.
3. Add mushrooms, garlic, 3/4 teaspoon salt, thyme, and rosemary. Cook, stirring occasionally, until the liquid from mushrooms has evaporated and they start to brown, 10 to 15 minutes.
4. Transfer the mushrooms and onions to a bowl.
5. Meanwhile, combine the eggs, milk, flour, remaining 1/2 teaspoon salt, and black pepper in the jar of a blender. Blend for a few seconds until the mixture is smooth.
6. Clean the skillet and wipe dry with paper towels.
7. Add the remaining tablespoon of butter and turn the heat to low. When butter has melted, swirl the pan so the butter coats the bottom and sides of the skillet. Turn off the heat.
8. Add the mushrooms and spread into a single even layer.
9. Pour in the batter.
10. Transfer the skillet to the oven. Cook until the mixture has puffed up slightly and is starting to brown on top, 25 to 30 minutes.
11. Carefully remove pan from the oven, and cut into wedges.
12. Serve warm or at room temperature.