Of course most taro ice creams don't taste much like taro at all, since the pale, sticky tuber can be hell to work with and free-flowing purple powders are so widely available (wholesale, anyway). But in the home kitchen, taro ice cream made with real-deal taro is more than worth the small effort: the root's delicately sweet, vanilla-coconut flavor is brought out well by dairy, and the texture is as creamy as can be.
You can find taro in most well-stocked Chinese markets. The tubers are sold in thick logs; look for moist cut edges and skin that's smooth and slightly glossy, not wrinkled. Leftover tuber is great to cube and fry for a potato side dish or to simmer in a vegetable curry.
To wrangle your taro into submission (and it's a big, ugly sucker to wrangle), slice off the skin with a knife, grate it by hand or in a food processor, and fry it in a little butter to drive out moisture and build caramelized flavors. Then simmer it with cream, coconut milk (for added nuttiness), and sugar until the shreds fall apart and the liquid is thick and starchy. Blend it up, strain it, and chill until it's cold enough to churn. No need to separate eggs or cook a custard—the taro's high starch content adds all the texture insurance you need.
All that starch does mean that the ice cream freezes rock solid if you leave it overnight. But if you let it rest on the counter for a few minutes it'll revert back to its scoopably soft self, and it'll carry all the naturally sweet, pleasantly starchy taste of taro minus the typical tooth-aching dose of sugar. Now isn't that better than some bright purple bubble tea made with cheap powder?