Rinse and dry the chard. Using a sharp paring knife, cut out the red stem from the leaves. You can save these or discard. If you choose to save them (they have sort of a rhubarb consistency), chop them into 1-inch pieces and set aside. Tear the leaves into roughly 2-inch pieces and place in a separate bowl.
Heat the olive oil over medium-high heat in a large heavy-bottomed skillet. Add the garlic and saute for 1-2 minutes or until fragrant and just beginning to brown. Add the stems (if using) and saute 2 minutes to soften. Add the leaves and saute for 2-3 minutes or until wilted and bright green. Season with salt and pepper to taste. Serve immediately.