sweet potato or yam?!?

tan-skinned sweet potato, red-skinned sweet potato, russet, red-skinned potato, Yukon Gold, and white-skinned potato

Is it a sweet potato or is it a yam? Often in our grocery stores, reddish-skinned sweet potatoes are labeled as yams.  In truth, it is extremely rare to find a true yam in a standard market, just about the only place you may be able to find them is in a Latin American market.  There is no need to worry though, if you have a favorite yam recipe, sweet potatoes will fit the bill, because in all honestly, that’s probably what you’ve been using all along.

A true yam is the tuber (or bulb) of a tropical vine and is not even distantly related to the sweet potato. Slowly becoming more common in US (Latin) markets, the yam is a popular vegetable in Latin America and the Caribbean. Yams are revered as religious objects and have ceremonial status, one reason may be because they can become amazingly huge. On the Pacific Island of Ponape, the size of yams is described as 2-man, 4-man, or 6-man, indicating the number of men need to lift the thing!  In fact, a 650-pound, 7-foot-long yam has been recorded.

a true yam

The yam tuber has brown or black skin, which resembles the bark of a tree, and off-white, purple or red flesh, depending on the variety. They grow in tropical climates, primarily in South America, Africa, and the Caribbean. Yams contain more natural sugar than sweet potatoes and have higher moisture content.

The sweet potato is grown in tropical America and is a part of the Morning Glory family. There are two varieties of sweet potato you will generally find. The paler-skinned sweet potato has a thin, light tan skin with pale yellow flesh, which is not sweet and has a dry texture similar to a white baking potato. The darker-skinned variety (which is most often called “yam” in error) has a thicker, dark orange to reddish skin with a vivid orange, sweet flesh, and a moist texture.  Sweet potatoes are very high in vitamins A and C. Sweet potatoes have a reputation as one of the most densely nutritious foods around. Just as with regular potatoes, do not store in the refrigerator, but rather in a cool, dark, dry place, with plenty of airflows. Sweet potatoes can be prepared like a potato: baked, boiled, sauteed, steamed, microwaved, or fried. For a new twist, substitute sweet potatoes in any of your favorite potato recipes, you may like it better than the original!

sliced potatoes and onions before watercress cream and cheese are added

Mixed Potato-Watercress Gratin

1 of each; red sweet potato, tan sweet potato, russet potato, Yukon Gold potato, red-skinned potato and white-skinned potato (about 4 pounds total), each peeled and thinly sliced
1 of each; large red onion and large yellow onion, each peeled and thinly sliced
1 tablespoon salt
4 tablespoons (1/2 stick) unsalted butter, divided
2 ounces watercress leaves, coarsely chopped, stems discarded
1 cup fat-free half-and-half
1 cup heavy cream
2 garlic cloves, peeled and finely minced
1 cup shredded Fontina cheese

Place the potato and onion slices in a large pot and add cold water, just to cover.  Add salt and bring to a boil.  Remove from heat and drain.

Preheat the oven to 350 degrees.

In the same pot, melt 2 tablespoons of the butter over medium heat, when melted; add the watercress and sauté for about 2 minutes until the watercress is wilted.  Pour in half-and-half and cream and cook for 5 minutes to thicken slightly.

finished mixed potato-watercress gratin

Rub a 3-quart (9×13-inch) glass baking dish with 1 tablespoon of the remaining butter, then cut up the last tablespoon of butter and dot around the dish, and scatter the minced garlic evenly over the bottom of the baking dish.  Pour the drained potato and onion slices into the dish and season with salt and pepper. Pour the creamy watercress mixture over the top. Sprinkle with the shredded cheese.

Bake on the middle shelf of the oven for 1 hour, or until the top is golden brown and the liquid is absorbed.  Allow to set at room temperature 5 to 10 minutes before serving.

Serves 8