(i had to use juice oranges and orange juice to make up the difference, as i was so not prepared for this recipe -- i saw blood oranges in the store, and couldn't resist. i had no idea how many you would need, but using orange juice worked just fine.)
put through a sieve.
make ice cream.
ps. this works for all citrus juices.
orange -- use juice oranges. they will give you way more juice than a regular orange.
grapefruit -- made it last summer. awesome.
lemon -- although i would add lemon zest. and maybe more sugar.
lime -- again, add zest and more sugar. for this you are going for a limeade phenomenon. (one of my favs.)
maybe i make a lot of citrus sorbets.
pps. i may have stolen the basis for this recipe from dolcetto. see the recipe here.