Yam-Apple Casserole (Shallow Thoughts)

Yam-Apple Casserole

Yams. I love 'em. (Actually, technically I mean sweet potatoes, since what we call "yams" here in the US aren't actual yams, but the root from a South American plant, Ipomoea batatas, related to the morning glory. I'm not sure I've ever had an actual yam, a tuber from an African plant of the genus Dioscorea).

But what's up with the way people cook them? You take something that's inherently sweet and yummy -- and then you cover them with brown sugar and marshmallows and maple syrup and who knows what else. Do you sprinkle sugar on apples before you eat them?

Normally, I bake a yam for about an hour in the oven, or, if time is short (which it usually is), microwave it for about four and a half minutes, then finish up with 20-40 minutes in a toaster oven at 350°. The oven part seems to be necessary: it brings out the sweetness and the nice crumbly texture in a way that the microwave doesn't. You can read about some of the science behind this at this Serious Eats discussion of cooking sweet potatoes: it's because sweet potatoes have an odd enzyme, beta amylase, that breaks down carbohydrates into sugars, thus bringing out the vegetable's sweetness, but that enzyme only works in a limited temperature range, so if you heat up a sweet potato too fast the enzyme doesn't have time to work.

But Thanksgiving is coming up, and for a friend's dinner party, I wanted to make something a little more festive (and more easily parceled out) than whole baked yams.

A web search wasn't much help: nearly everything I found involved either brown sugar or syrup. The most interesting casserole recipes I saw fell into two categories: sweet and spicy yams with chile powder and cayenne pepper (and brown sugar), and for yam-apple casserole (with brown sugar and lemon juice). As far as I can tell it has never occurred to anyone, before me, to try either of these without added sugar. So I bravely volunteered myself as test subject.

I was very pleased with the results. The combination of the tart apples, the sweet yams and the various spices made a lovely combination. And it's a lot healthier than the casseroles with all the sugary stuff piled on top.

Yam-Apple Casserole without added sugar

Ingredients:

• Yams, as many as needed.
• Apples: 1-2 apples per yam. Use a tart variety, like granny smith.
• chile powder
• sage
• rosemary or thyme
• cumin
• nutmeg
• ginger powder
• salt

Peel and dice yams and apples into bite-sized pieces, inch or half-inch cubes. (Peeling the yams is optional.)

Drizzle a little olive oil over the yam and apple pieces, then sprinkle spices. Your call as to which spices and how much. Toss it all together until the pieces are all evenly coated with oil and the spices look evenly distributed.

Lay out in a casserole dish or cake pan and bake at 350°F until the yam pieces are soft. This takes at least an hour, two if you made big pieces or layered the pieces thickly in the pan. The apples will mostly disintegrate into little mushy bits between the pieces of yam, but that's fine -- they're there for flavor, not consistency.

Note: After reading about beta-amylase and its temperature range, I had the bright idea that it would be even better to do this in a crockpot. Long cooking at low temps, right? Wrong! The result was terrible, almost completely tasteless. Stick to using the oven.

I'm going to try adding some parsnips, too, though parsnips seem to need to cook longer than sweet potatoes, so it might help to pre-cooked the parsnips a few minutes in the microwave before tossing them in with the yams and apples.