Good accompaniment to Prime Rib.
I use whatever potato or yams available or in season. My preference is Yukon Potato and the white yam.

1 lb yam, peeled, cut up in bite-sizes
2-3 lbs potatoes, peeled or partially peeled, cut up in bite-sizes
1 big Vidalia onion (it’s sweeter than the regular one), peeled, and cut into bite-sizes
Soak these in salted water.

In a grocery bag (make sure there’s no hole on the bottom), drop in onion, yam and potatoes. Season with salt, pepper (I use Seasoning Salt and Rosemary Seasoning Salt).
Shake them well.

Drop them in a shallow baking pan. Drizzle with Olive oil.

Bake for 45 min in 350 degrees oven.