Step 1: You will need:
Fat-free plain yogurt
Blueberries (frozen or fresh)
Zip-top plastic quart bag (the freezer kind, they are thicker and more sturdy)
Frozen fruit juice - Apple/Cherry or any other red kind
Fat-free sweetened condensed milk
Lychee instead of longan (a little sweeter, but a little harder to work with)
Cream cheese instead of yogurt
Raspberries instead of blueberries
Step 2: Strain the yogurt overnight
Put the yogurt into a strainer. Break it up as you remove it from the container. This helps the liquid to drain easier than leaving it in one big block.
Cover it with plastic wrap and leave it overnight in the refrigerator. Be careful of having any unsealed onions or other aromatic item as the yogurt will absorb those odors.
Step 3: The next day, remove the yogurt.
The yogurt should have a soft cheesy-like consistency. It will have reduced by about half its volume. The leftovers can be used as a healthful and non-fat alternative to sour cream or cream cheese in many cases.