Mushroom Popover Pie

This recipe came in handy when I was looking for a vegetarian recipe and didn’t have much inspiration. It’s actually quite tasty, though I’d use less salt next time. The pie was thin and not too filling, so I’d serve it alongside something more substantial, like a green salad with vegetables, for a light meal.

2 Tbsp. butter, margarine or vegetable oil, divided
½ cup minced red onion (about ½ a medium onion)
½ lb. white mushrooms, stems removed, chopped into ¼-inch pieces (about 2 cups)
¼ lb. shiitake mushrooms, stems removed, chopped into ¼-inch pieces (about 1 cup)
1 medium garlic clove, minced (about 1 tsp.)
1 ¼ tsp. table salt (I’d use less)
½ tsp. dried thyme
¼ tsp. dried rosemary (I used some chopped fresh rosemary from the garden)
3 large eggs, at room temperature
1 cup lactose-free milk
1 cup all-purpose flour
1/8 tsp. freshly ground black pepper

Adjust the oven rack to the middle position and preheat the oven to 375 °F. 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.

Add mushrooms, garlic, ¾ tsp. salt, thyme, and rosemary. Cook, stirring occasionally, until the liquid from mushrooms has evaporated and they start to brown, 10 to 15 minutes. Transfer the mushrooms and onions to a bowl.

Meanwhile, combine the eggs, milk, flour, remaining ½ tsp. salt, and black pepper in the jar of a blender. Blend for a few seconds until the mixture is smooth. (I did this in a bowl and it was fine.)

Clean the skillet and wipe dry with paper towels. 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. (I didn’t do this, because I didn’t want to burn myself or waste too much time waiting for the skillet to cool. I just put in the rest of the oil, spread it around in the heated skillet, and put the mushroom mixture back in.) Add the mushrooms and spread into a single even layer. Pour in the batter. 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.

Carefully remove pan from the oven, immediately slip a silicone oven mitt over the handle (I learn from my mistakes), and cut the pie into wedges. Serve warm or at room temperature.