Bake, microwave, or boil the potatoes in their skins until they can be pierced through but are still firm. Plunge into cold water, then peel once cool enough to handle and cut into 1-inch chunks.

Drain the tofu and blot very well between layers of paper towels, or press it in a tofu press for a few minutes. Cut into chunks roughly the same size as the potato.

Preheat the oven's broiler. Thread the potato and tofu chunks onto metal skewers, alternating as you go, for about 8 skewers.

Arrange the skewers on a lightly oiled, foil-lined baking sheet and spoon barbecue sauce generously over the potato and tofu.

Broil for 5 minutes, then carefully turn the skewers (use a long oven mitt) and broil for another 5 minutes. Turn once more and broil a final 5 minutes if needed, until touched with brown spots. Add more sauce partway through if the skewers look dry.

Remove from the oven and serve at once, with extra barbecue sauce on the side.