Stir together first 8 ingredients. Tear tortillas into 1-inch pieces; layer one-third of tortilla pieces in a lightly greased 6-qt. slow cooker. Top with one-third of chicken mixture and 2/3 cup cheese. Repeat layers twice.
Cover and cook on LOW 3 1/2 hours or until bubbly and edges are golden brown. Uncover and cook on LOW 30 minutes.
For an easy side, whisk together 1/3 cup white balsamic vinegar and 1/4 cup pepper jelly. Toss with 1 quartered and thinly sliced English cucumber, 1 quartered and thinly sliced small red onion, 4 cups fresh arugula, 2 cups halved grape tomatoes, and 1 cup diced yellow bell pepper.