Watercress is commonly used in salads so I decided to search for a different recipe using watercress. Did you know that pesto can be made using something other than basil? Well, watercress is a great option to making a delicious pesto. Check out the following recipe… Grilled Flat Iron Steak with Watercress Pesto. It is the perfect summer grill out recipe and the pesto adds so much flavor to an already yummy slice of meat. Note: This recipe uses almonds instead of pine nuts as well.