large sweet onion, such as Vidalia, cut into chunks
1 Pierce potatoes with fork. Microwave on HIGH 4 to 6 minutes or until tender, turning over halfway through cooking. Let stand 5 minutes or until cool enough to handle. Halve potatoes, then cut into 1/8-inch thick slices. Remove husks and silk strands from corn. Cut each ear into 4 pieces.
2 Mix butter, lemon juice, mustard, garlic, paprika, black pepper and red pepper in large bowl. Add shrimp, corn, sausage and onion; toss to coat well.
3 Place potatoes in even layer in 13x9x3-inch disposable foil pan. Top with shrimp mixture. Arrange shrimp so that they are at the top to avoid overcooking. Cover pan tightly with foil to prevent steam from escaping.
4 Place pan on grill over medium-low heat. Close lid. Grill 20 to 25 minutes or until shrimp are pink and vegetables are tender.