Peel and cut onions into 1/6-inch lengthwise so that they are still attached at the base. Mix lime juice, fresh garlic and sesame oil. Marinate all the seafood, zucchini, mushrooms and corn rounds in this mixture 4-6 hours, turning twice. Steam carrots and onions over hot water for 4 minutes. Assemble foods on skewers so that seafoods and vegetables alternate. Make sure foods are securely skewered. (For zucchini, poke skewer through the skin.) Add 2 tbs. Calvert's Cedar Street Dill Mustard to marinade juices. Brush over skewers while grilling. Grill over medium hot barbecue (preferably hardwood) flame about 8 minutes or until browned on exterior but moist inside. Serve with additional Dill Mustard.