Step 1: Preheat oven and prepare the baking dish.
Step 2: Cut chicken into evenly sized pieces for even cooking.
Step 3: Mix sour cream, mayonnaise, garlic, herbs, salt, and pepper in a bowl.
Step 4: Fold chicken and artichokes into the sauce mixture.
Step 5: Spread the mixture evenly in the baking dish.
Step 6: Sprinkle mozzarella and Parmesan evenly on top.
Step 7: Bake until cheese is melted and lightly browned and chicken is fully cooked.
Step 8: Let the casserole rest for a few minutes before serving.