Mix crackers, cereal and nuts. Spread out in a rimmed baking sheet. Melt butter and stir in ranch dressing mix and garlic salt. Pour butter mixture over crackers in pan. Stir well to coat pieces. Sprinkle with half of Parmesan and stir again.

Bake at 275 for 20 minutes. Remove from oven and stir well. Return to oven for another 20 minutes. Remove from oven and sprinkle with remaining cheese. Stir once more and turn out onto a large arrangement of paper towels. Let cool completely and then store in a large tightly covered container or jars. Makes about 1 gallon of mix