app/Models/Observers/InventoryObserver.php
public function deleted(Inventory $model)
    {
        $stocks = $model->stocks()->get();

        if (count($stocks) > 0) {
            foreach ($stocks as $stock) {
                $stock->delete();
            }
        }
    }
public function deleted(Inventory $model)
    {
        $stocks = $model->stocks()->get();

        if (count($stocks) > 0) {
            foreach ($stocks as $stock) {
                $stock->delete();
            }
        }
    }
Captures the Inventory models deleted event
and cascades the delete to all of it's stocks.

@param Inventory $model