Season and sear chicken breast in a hot skillet with olive oil until golden, then shred it finely—this creates texture and prevents dry, overcooked chicken when baked in the casserole.

Toast cumin, chili powder, and coriander in the same skillet after cooking chicken to release their essential oils and deepen their flavors before adding other ingredients.

Always drain black beans, corn, and Rotel tomatoes thoroughly to prevent excess moisture that will make the casserole soggy and prevent crispy tater tots.

Keep tater tots in the freezer until the last moment and arrange them directly on the hot filling—they'll crisp up perfectly without absorbing moisture from the cheese and sour cream mixture.

Cover the casserole loosely with foil for the first 20 minutes of baking, then uncover for the final 10-15 minutes to allow tater tots to brown evenly without the cheese burning.