Cut the greens just at the base, where the leaf meets the stem. Set leaves aside. Trim cut ends from stalks and cut stalks into small pieces. Set aside.
Stack a few chard leaves and roll tightly. Slice rolled leaves into strips. Repeat with remaining leaves.
Wash and dry cut leaves and stalks.
Add canola oil to sauté pan over medium heat. Add a couple of handfuls of greens and cook until bright green and wilted. Add garlic and stir well. Add remaining greens a handful at a time until all greens are wilted and bright green. Season with salt and pepper.