Fresh tomatillos have a sticky coating underneath their papery husks, which is why they need to be rinsed before using.
1/2 lb. fresh tomatillos, husked and rinsed
2 fresh serrano chiles
1/2 small white onion, chopped
3 tbsp. cilantro leaves
Juice of 1 lime
4 flour tortillas (12 inches)
3 1/2 cups shredded cooked chicken (such as rotisserie), seasoned to taste
2 1/2 cups shredded Oaxaca or Cheddar cheese
Sour cream (optional)
1. Preheat the broiler. Place tomatilos and serranos on a baking sheet. Broil turning once, until slightly charred, 5 to 7 minutes; discard chile stems.
2. In a blender, combine tomatillos, serranos, onion, cilantro, lime juice, and salt to taste and puree until well blended; set the salsa aside.
3. Heat large skillet over medium heat. Toast tortillas one at a time until puffed and very lightly browned, about 1 minute per side.
4. Lay tortillas on a work surface. On half of each tortilla, place one-fourth of the chicken, one-fourth of the cheese, and about 2 tbsp. tomatillo salsa. Fold tortillas in half.
5. In a lightly oiled skillet or grill pan over medium heat, cook one quesadilla at a time until crisp and golden brown on both sides. Add more oil if necessary for remaining quesadillas. Transfer to a cutting board and let cool slightly. Slice into wedges and serve with remaining salsa and sour cream, if desired.