Cheese Popovers with French Onion Butter

While popover batter could not be simpler, getting the best results takes practice. After several tests, I’ve discovered a few fail-proof tips along the way: 

• While you may be tempted to make this recipe in a muffin tin, you will get the best results with a popover pan. The pan has more air circulation and the tall, narrow cups help you get sky-high popovers. If you like to make popovers with any regularity, then it is worth investing in a proper pan. (I like this cherry red one from Neiman Marcus!)

• Preheating your popover pan is an essential step. When the batter hits the hot pan, it creates steam and this steam is what gives popovers their dramatic towering shape. You want this process to start happening immediately.

• When mixing up your batter, you want to whisk the milk and eggs well until you see small frothy bubbles. These bubbles are what help your popovers rise.

• Do not overfill your popover pans—you want to leave space for them to rise. If you add too much batter, they will “pop” too soon and risk falling over and looking misshapen. 

• After rotating the pan halfway through baking time, do not open the oven door again until the popovers are done; this will help them rise evenly.

• Popovers lose their crunch if they linger in the pan, so turn them out onto a wire rack immediately. Using a paring knife, poke a small opening in the side of each popover to let the steam escape. This will help them hold their shape and texture until they get to the dinner table. No one wants a soggy popover!

• Save any leftover popovers for breakfast the next morning! Halve them lengthwise and arrange in a baking dish. Crack an egg into each well and top with cheese, herbs, chopped ham, cooked vegetables, etc.. Bake at 400°F for about 10 minutes, or until the whites are just set and the yolks are still runny.

Makes 6 Popovers

French Onion Butter

• 2 sticks unsalted butter (1 cup) plus 2 Tablespoons unsalted butter, at room temperature

• 1 medium yellow onion, very thinly sliced

• Kosher salt and freshly ground black pepper

• 2 Tablespoons Cognac or brandy (optional)

• 1 Tablespoon fresh thyme leaves

• 2 teaspoons fresh lemon zest

Popovers

• 1½ cups whole milk

• 3 large eggs, at room temperature

• 1½ cups all-purpose flour

• 1½ teaspoons kosher salt

• 2 ounces shredded Swiss cheese

• 1 ounce finely grated parmesan cheese

• Melted butter or nonstick cooking spray, for greasing

1. Make the French Onion Butter In a medium skillet, melt 2 tablespoons of the butter. Add the onion and a ¼ teaspoon of salt. Cook over moderate heat, stirring occasionally, until golden brown, about 25 minutes. (If the onion begins to stick, add a splash of water. If they start to darken too quickly, lower the heat.) Add the Cognac, if using, and cook until evaporated, about 2 minutes. Let the onions cool completely.

2. In a medium bowl, mix the caramelized onions with the thyme leaves, lemon zest and the remaining 2 sticks of softened butter until combined. Season with salt and pepper. Spoon the butter onto a ramekin. If not using right away, refrigerate the butter. Bring to room temperature before serving.

3. Make the Popovers Set a 6-cup popover pan on the bottom rack of the oven (leaving ample room between the pan and the rack above it). Preheat the oven to 450°F.

4. In a small bowl, combine the parmesan and Swiss cheeses.

5. In a small saucepan, warm the milk until small bubbles begin to form around the edges. In a medium bowl, whisk the eggs until they look frothy. While whisking constantly, gradually stream in the warm milk, being careful not to let the eggs cook. Whisk vigorously until small bubbles appear. Using a fine mesh sieve, sift the flour and salt into the bowl and whisk until smooth. 

6. Remove the popover pan from the oven and coat the cups with nonstick spray. Fill the prepared cups three-quarters of the way with the popover batter and sprinkle the cheese mixture on top (about 1 heaping tablespoon per popover).

7. Return the pan to the oven and bake for 20 minutes. Rotate the pan 180 degrees and then reduce the oven to 350°F. Continue baking until the popovers are golden brown and puffed, 15 to 20 minutes more. Do not open the oven after rotating the pan.

8. Invert the popovers into a wire rack and prick each one with the tip of a paring knife to let the steam escape (this helps the popovers stay crunchy!). Serve right away, passing the French onion butter at the table. 

NOTE This recipe can be easily doubled. If so, double the batter and bake in two batches. After baking your first batch, use a paper towel to wipe out the popover cups, then return the pan in the oven for 5 to 10 minutes. Repeat the baking process with the remaining popover batter. This recipe makes enough French onion butter for 12 popovers.