2 pounds fresh tomatillos, dehusked and washed
1 medium yellow onion, sliced
6 fresh serrano chiles or 3 jalapeños, stemmed
2 tablespoons canola oil
3/4 cup chopped cilantro, leaves and stems
1 1/2 teaspoons salt (or to taste)

Place tomatillos, onion, and chiles in a large skillet or on a griddle. Drizzle with 1 tablespoon oil and roast over medium heat for approximately 10 minutes, turning occasionally. In a blender, combine tomatillo mixture with cilantro and salt and blend until smooth. Heat remaining oil in a 2-quart saucepan or pot. Add sauce and cook over medium heat for 5 minutes; set aside.

Chicken Filling

2 1/2 pounds boneless, skinless chicken thighs
1/4 cup (1/2 stick) butter
1/3 cup diced green bell pepper
1 1/3 cups diced yellow onion
3/4 cup diced fresh, unpeeled tomatoes
1 teaspoon minced garlic
1 teaspoon salt
1 teaspoon freshly ground black pepper
1 1/2 teaspoons ground cumin
3/4 teaspoon ground Mexican oregano
3/4 cup whole, peeled canned tomatoes, puréed with juice from can
3/4 cup canola oil
16 to 20 white-corn tortillas (6-inch size)
1 pound Monterey Jack cheese, grated

Preheat oven to 350 degrees. In a saucepan, boil chicken thighs until tender, about 20 minutes. Drain and shred meat or cut into 3/4-inch cubes; set aside. In a 2-quart saucepan or pot, melt butter. Add bell pepper, onion, and fresh tomatoes and cook over medium heat until soft, about 5 minutes. Add chicken, garlic, salt, pepper, cumin, oregano, and puréed tomatoes and continue cooking for 15 minutes. Set aside.

In a large skillet, heat canola oil to 300 to 325 degrees (medium heat). Using tongs, place tortillas in oil one at a time and cook until pliable, about 1 or 2 seconds per side; be careful not to fry them. Stack, with a paper towel between each one, to drain.

Divide chicken filling equally among tortillas and roll into enchiladas. Place in an oven-safe dish and top with tomatillo sauce and grated cheese. Bake until cheese melts, about 5 minutes. Makes 16 to 20 enchiladas.