Good question. Braising is a combination of dry heat and moist cooking. Typically you brown the ingredients over relatively high heat first to develop flavor, and then you add a smallish amount of liquid, turn down the heat, and cook low and slow to tenderize. When braising tough cuts of meat, this method applies directly. When braising vegetables, as in this recipe, the technique depends on the nature of the veggies. In this case, we don't want to brown the kale. So we sauté the aromatics first (in this case the garlic) and then add the liquid and the kale to cook low and slow.