Vegetables in aluminum foil packets are a barbecue favourite—just be sure to seal the packs tightly and be careful of escaping steam when opening. Since sweet potatoes cook faster than regular ones, cutting them into larger pieces helps all the vegetables cook evenly.
3large yellow-fleshed potatoesdiced in half-inch pieces (about 4 cups)
1sweet potatopeeled and diced in one-inch pieces (about 2 cups)
1large oniondiced
6ice cubes
salt and freshly ground pepperto taste
Instructions
Cut 4 large foil sheets; divide into two stacks on work surface. Generously spread top of each stack with 1/4 cup of the butter.
In a large bowl, stir together potato, sweet potato, and onions.
Divide potato mixture evenly between buttered foil pieces. Top each pile with dollops of remaining butter, and season with salt and pepper. Add 3 ice cubes to each pile (see tip, below). Fold and seal double-thickness packets, crimping seams tightly and leaving air space inside for steam.
Place packets on a preheated medium grill, turning about every 10 minutes, being careful not to puncture foil. Cook until packet contents feel soft when pressed gently with tongs, 45–50 minutes. Carefully open foil to serve.
Tip:Ice cubes add steam while packets are cooking and are easier to wrap than water. Leaving the skin on the potatoes helps them keep their shape.