Heat a skillet over medium heat. Place the chopped bacon in the skillet and cook until the fat separates from the meat. Melt the butter in the skillet. Stir in the lemon juice and garlic paste. Add the Swiss chard to the butter mixture. When the leaves begin to wilt, place a cover on the skillet and increase heat to medium-high. Allow the chard to cook while covered for about 4 minutes. Stir the chard leaves to coat with the butter mixture. Season with salt and pepper.