This recipe is perfect ... skip browning the brats. Cut the potatoes lengthwise in half and tuck in around the outer edges of the Dutch oven pot with a sprig of fresh thyme or rosemary.
Prepare grill for direct cooking. Cut lengthwise almost through bratwurst. Grill, turning often with tongs, until cooked through and browned, about 10 minutes. Meanwhile, heat butter in large skillet.