Wash chard by gently submersing in cool water several times.
Remove the stems from leaves and chop stems into 1 inch pieces. Set aside. Stack the washed leaves and roll them in to a long scroll. Using a sharp knife, cut the scroll in quarters.
Heat a skillet or heavy dutch oven over medium-high heat, add the olive oil and chopped stems and saute for 5 minutes.
Add the garlic and saute for an additional 15-20 seconds.
Add the wet chard leaves, one handful at a time, stirring after each addition.
After all the leaves have been added, immediately cover the pan with a tight fitting lid and continue cooking over high heat for about 2 or 3 minutes. Uncover and cook just until most of the liquid has evaporated (another 1 minute or so).
Squeeze a couple of wedges of fresh lemon over prepared chard, season to taste with salt and pepper and serve immediately.