Heat the broiler. Arrange the tomatillos, poblano, serrano, onion, and garlic on a baking sheet.

Broil until the tomatillos have softened and blistered and the poblano is charred in spots, turning the vegetables as necessary.

Transfer the poblano to a bowl and cover it for about 10 minutes. Peel away the loose charred skin, then remove the stem and seeds.

Add the roasted tomatillos, poblano, serrano, onion, garlic, cilantro, chicken broth, and salt to a blender.

Blend until smooth.

Pour the green sauce into a saucepan and bring it to a gentle simmer over medium heat. Cook for about 5 minutes.

Reduce the heat to low. Stir in the Mexican crema until completely incorporated. Taste and adjust the salt. Avoid aggressively boiling the sauce once the crema has been added.

Preheat the oven to 375°F.

Spread a thin layer of the creamy green sauce across the bottom of a 9×13-inch baking dish.

Heat a small amount of oil in a skillet over medium heat. Briefly pass each tortilla through the warm oil for just a few seconds per side until softened. Transfer to a paper towel-lined plate.

Place shredded chicken down the center of each tortilla.

Roll each tortilla snugly and arrange it seam-side down in the baking dish.

Pour the remaining creamy green sauce evenly over the enchiladas.

Cover generously with shredded Oaxaca cheese.

Bake for 15 to 20 minutes, until the sauce is bubbling around the edges and the cheese has completely melted.

For a little extra color, switch the oven to broil for the final minute or two. Watch carefully.

Let the enchiladas rest for about 5 minutes.

Finish with sliced onion, fresh cilantro, and an extra drizzle of crema if you like.