Chard leaves can be prepared like spinach, and the stalks like asparagus. In fact, its leaves serve as a good substitute for spinach in most recipes, but they will need to be cooked slightly longer.
Chard may be steamed, sautéed, or braised, and it can be added to soups, stews, and casseroles. The leaves and stems may be cooked and served together, or prepared separately as two different vegetables.
For salads and sandwiches, it's best to use young, tender leaves. For a simple side vegetable, leaves of medium size can be quickly sautéed - the stalks can be prepared this way, too. Older leaves and stalks are best steamed, boiled, or added to soups, as the stems require a longer cooking time to become tender than the leaves do.
Like other leafy vegetables, chard needs to be thoroughly washed before cooking since sand and other debris tend to nestle in its leaves. Instead of using a colander and running water over the leaves, the best way to remove debris from leafy greens is to dunk and soak them in plenty of water. Place the leaves in a large bowl, pot, or sink filled with cold water. Agitate the leaves one by one, then remove individual leaves by hand and place them in another container. Pour out the water and repeat the procedure until the water is free of debris. If you will be using the greens in a salad, dry them in a spinner.
To sauté: Heat a cast iron pan over medium-high heat, add olive oil and chopped stems and sauté for five minutes. Add the garlic and sauté for an additional 15 seconds. Next, add the wet chard, 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. Allow the leaves to cook for about five minutes. Remove the lid and continue cooking over high heat until all the liquid has evaporated, about 2 to 3 minutes. Season with salt and pepper to taste. Serve immediately with a splash of fresh lemon