Combine oil, mustard, thyme, salt and pepper in a large bowl. Whisk to blend well. (Can be prepared 6 hours ahead. cover and let stand at room temperatue.) Prepare barbecue (medium-high heat.) Add potatoes and onions to mustard oil. Toss to coat. Set 1 long sheet of heavy duty aluminum foil (or 2 sheets of regular) on work surface. Spray foil with PAM. Place vegetables in center of foil. Pour remaining oil over. Cover with more foil; roll in top and bottoms of foil - then each end to make a package. Seal tightly. Place package on grill; cook approximately 25 minutes. Remove from grill, slit package top; fold back and garnish with thyme sprigs. Posted to EAT-L Digest 24 Aug 96 Date: Sun, 25 Aug 1996 19:29:40 -0400 From: Laura Hunter