When the first Zen master came to China, he instructed his disciples to observe and be mindful of the mind-and-body at all times. He instructed them to establish Right View and Right Mindfulness, and to discern things as they actually are. This was no different than the instructions found in the Four Foundations of Mindfulness, which has its source and authenticity from the Pali Canon. Therefore the Zen method was no different than the Four Foundations of Mindfulness in the Original Buddhism.
However, after the Sixth Patriarch of Zen's passing away, later Zen schools' methods are believed to be deviating from the original method. Many people began to look at the Zen as a spiritual practice for calmness of mind (Samatha) instead of the pursuit for Total Unbinding -.