Step 1

Heat the broiler to high and arrange a rack in the upper third of the oven. Line a rimmed baking sheet with aluminum foil.

Step 2

Trim the stems from 8 medium poblano peppers and halve lengthwise. Remove the core, ribs, and seeds. Place the peppers skin-side up on the baking sheet in a single layer (they can be touching) and press down on them as needed so they sit fairly flat. If they don’t all fit on the baking sheet, broil in 2 batches.

Step 3

Broil until the skin on the peppers is almost completely blackened and blistered, 5 to 12 minutes. Rotate the baking sheet as needed so they evenly blacken. Meanwhile, heat a large nonstick frying pan over medium heat. Remove the casings from 12 ounces to 1 pound uncooked Mexican chorizo and add to the pan. Cook, breaking up the meat into smaller pieces, until browned and cooked through (add 1 tablespoon vegetable oil to the pan if it is dry), 5 to 7 minutes. Remove the pan from the heat.

Step 4

When the peppers are ready, transfer to a large heatproof bowl and cover with the aluminum foil on the baking sheet. Let sit for at least 10 minutes to steam.

Step 5

Meanwhile, reduce the oven temperature to 375ºF. Coat a 9x13-inch baking dish with cooking spray. Shred 12 ounces Monterey Jack cheese on the large holes of a box grater (about 4 cups, or use 3 cups pre-shredded). Place 8 large eggs, 1 cup whole or 2% milk, 2/3 cup all-purpose flour, 1 1/2 teaspoons kosher salt, and 1 teaspoon baking powder in a blender and blend on high speed until smooth, scraping down the sides of the blender halfway through, 45 to 60 seconds total.

Step 6

Peel off and discard the skin from the peppers, using a paper towel to rub off any skin that doesn’t come off easily (do the best you can, it doesn’t all have to come off); it’s okay if the peppers tear.

Step 7

Pour enough of the egg mixture into the baking dish to just cover the bottom. Arrange half of the peppers in an even layer over the egg mixture. Using a slotted spoon, transfer the chorizo over the peppers in an even layer. Sprinkle with half of the cheese. Arrange the remaining peppers evenly over the cheese. Pour the remaining egg mixture evenly over the peppers, then sprinkle with the remaining cheese.

Step 8

Bake on the upper third rack until puffed, the center is set, and the edges are golden brown, 35 to 40 minutes. Let cool for 5 minutes before serving with salsa or hot sauce if desired.