This recipe is a great accompaniment to roast chicken or pork. Creating individual packets of yams may seem time-consuming, but it's worth the work. The sealed parchment pouches lock in flavors so the vegetable-herb mix becomes moist, tender and fragrant. None of the juices are lost in baking — and best of all, there's no sticky pan to wash! The packets can be made up to 4 hours ahead of baking. At serving time, let everyone open their own packet so they can spoon the syrupy juices that have collected in the packet over the yams.
Old World yams and New World sweet potatoes are different vegetables, but in the US today, the terms are often used interchangeably. At Earthbound Farm we produce the Garnet and Jewel varieties, which are commonly called yams but are actually sweet potatoes. No matter what you call them, though, they're delicious!
Position a rack in the middle of the oven and preheat to 375 degrees F.
Cut four 14x12-inch pieces of parchment paper (or aluminum foil) and arrange them on a work surface so that the short end is closest to you. Arrange a quarter of the yam slices on the bottom half (nearest you) of each piece of parchment paper, layering the slices neatly. Leave a 1-inch border (space) around the yams. Top with a quarter of the onion slices. Into each packet drizzle 1 tablespoon of oil, add 1 tablespoon of butter, and then sprinkle 1 tablespoon of brown sugar evenly over the yams.
Grind the salt and sage leaves in a spice grinder until well mixed. Sprinkle each packet with some of the sage salt and add freshly ground pepper to taste. Reserve unused sage salt for another use.
Fold the top half of the parchment over each pile of vegetables so that the edges meet. Starting at one end of the crease, seal the packet by folding the edge in a series of small, tight, overlapping pleats to create a half-moon-shaped package. Carefully transfer the packets to a rimmed baking sheet and bake for 40 minutes or until the yams are tender when poked with a skewer or the tip of a knife. Let the packets rest for 5 minutes before serving.