Dishwasher cooking was popularized by TV personality Bob Blumer, also known as the "Surreal Gourmet." His famous dishwasher-poached salmon recipe relies on the heat of your dishwasher's wash and dry cycles to lightly cook well-sealed salmon packets. You can try this trick with other foods, but because potatoes require high-heat cooking for extended times, you have to prepare your food carefully. Involve the kids in the preparation and baking process, and you may even get them to pitch in on the dishwashing, too.
To get the potatoes to cook through in the relatively low heat created by your dishwasher's wash and dry cycles, you need to cut the potatoes into very small pieces to expose them to the heat as much as possible. Quartering your potatoes lengthwise, then slicing each quarter into 1/8-inch slices should do the trick. Older kids can help slice and dice, or prep your potatoes up to this point yourself and then hand them over to the younger generation for seasoning and packaging.
Toss the potato slices with your favorite seasonings in a large bowl until the pieces are coated. You can use dry spices, such as ranch seasoning mix, with just a hint of oil for moisture, or use your favorite creamy dressing or marinade for flavor. Have the kids mix the potatoes with the seasoning thoroughly, which they can do with a spoon, salad tongs, or even by shaking the bowl aggressively if it has a tight-fitting lid.
Packaging for the Dishwasher
The key to cooking in your dishwasher is using heavy-duty aluminum foil folded into sealed, air-tight pouches. Use a large spoon or small ice cream scoop to dish out a small amount of seasoned potatoes onto a large piece of aluminum foil. Spread them out a bit so you have a single layer, then bring the two ends of the aluminum foil together above the potatoes and start rolling or folding them downward, like folding down the top of a paper lunch sack. Once this folded edge is tight against the potato layer, fold the remaining ends in toward the potatoes as well. If air comes out when you press down on the pouch, your packet isn't airtight enough for dishwasher cooking. Start over or double-layer your pouch. If the kids are handling this part of the process, check their pouches before placing them in the dishwasher.
Place the potato packets in a single layer on the top dishwasher rack, being careful not to poke through the pouches with the rack's wires. Have the kids load any dirty dishes from the prep work into the bottom of the dishwasher and add soap, if you like. The airtight packets will protect your food. Turn off any energy-saving features on your dishwasher before you attempt to cook the potatoes and let it run through the whole wash and dry cycle. If you have your water heater set low for safety or energy conservation, you may need to turn it up for this process, as you need as much heat as possible. If your first attempt at dishwasher cooked potatoes doesn't work, use smaller pieces the next time, or try shredding instead of chopping the potatoes.