Ingredients
Ingredients for Chile Relleno Casserole
This recipe uses simple ingredients, most of which you can find at any well-stocked grocery store. Here is what you need, along with suggested amounts as a guide. Adjust them to the size of your baking dish and your taste.
For the Casserole
- 6 to 8 poblano peppers. The star of the dish. Look for large, glossy, dark green peppers with smooth, firm skin and a flat shape that will be easy to open and layer.
- About 3 cups shredded Oaxaca or mozzarella cheese. Oaxaca cheese is the traditional choice. It melts beautifully and has a mild, slightly salty, milky flavor. Low-moisture mozzarella is an easy substitute.
- About 2 cups shredded Monterey Jack cheese. It adds a creamy, buttery melt and a bit of tang.
- Oil, for greasing the baking dish and the saucepan.
- 8 eggs, separated. Whipping the whites is what gives the casserole its light, airy texture.
- About 1/2 cup all-purpose flour. It gives the batter structure so it sets properly.
- About 1/2 cup milk. It loosens the batter and adds richness.
- 1 teaspoon baking powder. It gives extra lift.
- Salt and black pepper, to taste.
Instructions
Roasting is the most important step for flavor. Char the poblanos on all sides until the skin is blistered and blackened in spots. You can do this directly over a gas flame, under a broiler, or on a hot grill. Turn the peppers often so they char evenly.
Next, transfer the hot peppers to a covered dish or a bowl covered with a plate or plastic wrap, and let them steam for 10 to 15 minutes. The trapped steam loosens the skin from the flesh and softens the peppers.
Once they’re cool enough to handle, peel away the skins. Remove the stems and seeds, then cut a slit down one side and open each pepper into a flat piece. A little leftover char is fine, since it adds smoky flavor. Avoid rinsing the peppers under water, which washes away flavor. If a few seeds remain, wipe them off with a paper towel.
For the red salsa, place the Roma tomatoes, serrano chile, and chile de árbol in a pot with enough water to cover and simmer until softened, about 10 minutes. The tomatoes should be tender and the skins slightly split.
Transfer the softened tomatoes and chiles to a blender, along with a small amount of the cooking water if needed. Add the white onion, garlic, oregano, chicken bouillon, and salt. Blend until completely smooth. Taste and adjust the salt and spice level.
Heat a little oil in a saucepan over medium heat. Pour in the blended salsa. It will sizzle and spatter, so be careful. Cook until the salsa darkens slightly, thickens a little, and smells fragrant. Frying the salsa this way, a technique called sazonar, deepens the flavor and gives it a rounder, more savory taste. Keep it warm over low heat while you finish the casserole.
Separate the 8 eggs, placing the whites in a large, clean bowl and the yolks in another. Make sure no yolk gets into the whites, because even a little fat will keep them from whipping properly. The bowl and beaters should also be completely clean and dry.
Beat the egg whites until they form firm, glossy peaks. When you lift the beaters, the whites should stand up straight without drooping. This is the secret to the light, fluffy texture.
Add the flour, baking powder, salt, and black pepper to the whipped whites. Slowly mix in the milk, then add the egg yolks one at a time. Gently fold everything together until evenly combined. Use a spatula and a light hand, folding from the bottom of the bowl up and over, so you keep as much air as possible. Overmixing deflates the whites and leads to a dense casserole.
Lightly oil a baking dish. A 9×13-inch dish works well. Spread half of the egg mixture evenly over the bottom.
Add a layer of roasted poblanos on top of the egg mixture. Sprinkle on shredded Oaxaca (or mozzarella) and Monterey Jack cheese. Add a second layer of poblanos on top of the cheese.
Pour the remaining egg mixture evenly over the top, covering the peppers. Finish with more shredded cheese for a golden, bubbly crust.
Bake in a preheated oven (around 350°F to 375°F / 175°C to 190°C is a good range) until the casserole is golden, puffed, and completely set in the center. A knife inserted in the middle should come out clean, with no wet egg. Baking time varies with your oven and dish, but expect roughly 30 to 40 minutes. If the top browns too quickly, cover loosely with foil.
Let the casserole rest for 5 to 10 minutes before cutting. It will settle slightly as it cools, which is normal.
Cut into squares and serve hot with the warm homemade red salsa spooned generously over the top.