Preheat oven to 375°F.
Spread 2-3 tbsp of sauce in a 9x13" lasagna dish.
Layer lasagna sheets, sauce, and ⅓rd of chicken. Sprinkle mozzarella (about ¾ cups per layer).
Repeat for the second and third layers, saving some sauce and lasagna sheets.
For the final layer, cover with lasagna sheets, spread remaining sauce, and sprinkle mozzarella.