How to Make It
Preheat the oven to 350°. In a large, deep skillet of boiling water, cook the husked tomatillos and jalapeño over moderately high heat until softened, about 10 minutes. Drain the tomatillos and jalapeño, then transfer them to a blender and puree until the salsa verde is smooth.
Wipe out the skillet and heat the 1/4 cup of olive oil in it. Add the salsa and bring to a boil over moderately high heat. Season with salt and pepper. Spoon a few tablespoons of the salsa into each of two shallow 5-by-10-inch baking dishes.
In a medium skillet, heat 1/4 inch of olive oil until shimmering. Using tongs, dip a tortilla in the hot oil until coated and cook over medium heat, turning once, until pliable, about 10 seconds. With the tongs, carefully lift the tortilla out of the oil and dip it into the hot salsa, making sure to coat both sides. Transfer the tortilla to a large plate. Repeat with the remaining tortillas, stacking them on the plate.
Arrange 8 of the tortillas on a work surface and spoon the shredded chicken in the center of each one; season with salt and pepper. Roll the tortillas into loose cylinders and transfer them to one of the prepared baking dishes, seam sides down. Repeat with the remaining tortillas, filling them with the shredded cheddar cheese. Spoon the remaining salsa verde over the enchiladas and sprinkle them with the crumbled queso fresco. Bake for about 30 minutes until the enchiladas are hot and the salsa is bubbling. Serve the enchiladas with the sour cream, lime wedges, cilantro, onion, tomatoes and additional queso fresco on the side.