Step 1: Juice Some Ginger
I used a Jack LaLanne power juicer. Before buying the juicer, a jumping jack was simply an annoyance from elementary school physical education. But now, whenever I drink fresh juice from the juicer, I imagine myself preparing to tow 70 boats through the Golden Gate channel or to do a couple thousand push ups. Especially after vegetable juice with a handful of garlic cloves.
You could also use a grater and a sieve to extract the juice, but it would be a marathon effort -- probably the way Jack would actually do it.
Step 2: Blend a Bunch of Mangoes
Step 3: Freeze
Step 4: Ginger Glaze
For every one part of ginger juice, add somewhere between 3 to 4 parts sugar. Reduce over low heat just bringing it to a simmer. Be careful not to burn it or to boil it over. Once all the sugar is in solution let it cool.
If it's not thick enough, try adding some corn starch or potato starch. Remove some of the liquid, cool it and add the starch. Once dissolved, add the mixture back to the hot liquid. If you add the starch directly to the hot liquid you run the risk of it forming chunks that are nearly impossible to dissolve.
A four to one ratio yields a glaze a little gritty. Try for just under gritty, but super-saturated with sugar.