Using flameproof tongs, char the tortillas briefly on each side over an open flame, or toast them under a preheated broiler. Keep the tortillas warm by covering them with a kitchen towel.
In a medium microwave-safe bowl, combine the shredded chicken, black beans, and salsa. Cover the bowl with plastic wrap and microwave on high until the mixture is hot throughout, about 3 minutes. Stir in the cilantro.
Lay the tortillas on a work surface. Spoon one fourth of the chicken mixture over the bottom third of each tortilla. Top the chicken with the lettuce, cheese, and yogurt. Fold the sides of the tortillas in over the filling, and roll the tortillas up tightly to encase the filling. Serve immediately.