Heat oven to 425 degree F.
Prepare potatoes about 30 minutes prior to prepping the chicken
Peel potatoes, rinse and set aside
Slice the bottom of each potato to create a flat surface
Slice slits through potatoes about 1.¼ inch thickness leaving about ½ inch potato uncut near the bottom. It's important NOT to cut the potato through. A large metal spoon can be used as a guide, place a potato in a large metal spoon slice through potato until the blade hits the spoon. In essence, this keeps the potato whole leaving slits or slices to fill with butter and onion
Slice onions ¼ inch thick and butter into 1 tablespoon pats
Tuck one slice of onion and one slice of butter between each slice of potato, continue until all potatoes are filled (see photo above)
Wrap each potato with aluminum foil
Place potatoes on a baking sheet and cook in the oven at 425 F. for 40 minutes, test for doneness
To add smoky flavor, place wrapped, cooked potatoes on the grill the last 10 minutes of chicken cooking time