Preheat oven to 350F. Coat a lasagna pan with cooking spray.

Place chicken in medium saucepan and fill with enough cold water just to cover chicken. Set pan over high heat and bring to a boil. Reduce heat to medium and simmer until chicken is cooked through, about 10 to 15 minutes; drain. When chicken is cool enough to handle, cut into 1-inch pieces.

Transfer chicken to a large bowl and add beans, sour cream, 1 cup of shredded cheese, chilies, cumin, and pepper; mix well and set aside.

Arrange half of tortillas in bottom of prepared lasagna pan, overlapping pieces to cover surface. Top tortillas with half of chicken mixture, layer with remaining tortillas and then top with remaining chicken mixture. Sprinkle with remaining cup of cheese.

Bake until filling is bubbly and cheese is melted, about 30 minutes. Let stand 5 minutes before slicing into 12 pieces. Serve with salsa on the side.