Step 1Bring a large pot of water to boil. Add the tomatillos and boil just until they darken to an olive shade, about 5 minutes. Remove from heat, drain and set aside until cool enough to handle.
Step 2In a food processor, combine the boiled tomatillos with the onion, chiles, cilantro and salt. Pulse until the ingredients are blended to form a salsa. This makes a generous 6 cups of salsa, which can be covered and refrigerated until ready to use, up to 1 week.
Step 1Heat the oven to 350 degrees. Gently heat the salsa in a large saucepan until it is warm. When the salsa is warm, spoon about 1 cup of it to cover the bottom of a 13-by-9-inch baking dish.
Step 2In a medium skillet, heat the olive oil over medium heat until hot. Gently dip both sides of the tortillas into the oil to soften, then quickly dip each of them into the salsa to coat. (For a lower-fat enchilada, skip the oil. Simply heat the tortillas in a microwave until they are soft and pliable.)
Step 3Place the tortilla on a plate and fill with a scant 3 tablespoons shredded chicken. Roll or fold the tortilla over like a taco and place in the baking dish. Repeat until all of the tortillas are assembled.
Step 4Cover the assembled tortillas with the remaining salsa and dot with teaspoon-sized dollops of the Mexican cream. Sprinkle over the cheese.
Step 5Place the baking dish in the oven and heat until the cheese is melted and the enchiladas are warm, about 15 minutes. Remove from heat and serve immediately.