First of all, wait for a dry, cool day. You can't do this when it's humid. And you will need a deep fryer with a thermostat. You can do small batches in one of those Fry Baby things, but you're better off with one that has a basket rather than the slotted spatula thing for scooping stuff out of the oil. Walnuts covered in molten sugar are tricky to work with. You don't want to be chasing them around with a spatula. You want to be lifting them out of the boiling oil with a nice sturdy basket. We have a big Waring deep fryer, and we use it for just three things: 1) fried walnuts, 2) smelts for Christmas Eve, and 3) Clare's faschnachts. I can't remember the last time I deep fried anything else. Even so it was worth spending $100 and having this big honkin thing sitting on my counter top in the downstairs kitchen because those three things are just that good.
For each pound of fancy whole unroasted walnut halves, you need about 1-1/3 cup of sugar and 2/3 cup of water. The amounts are approximate. You should err on the side of more syrup rather than less syrup because extra sugar will just crystallize into walnutty sugar dust that you can use the next time you make a coffee cake or cobbler. And some of it melts into burned walnutty brittle in the deep fryer that you can crush in the food processor and sprinkle on ice cream. So don't skimp. Put the walnuts and sugar and water in a bigger pot than you think you need, because you want to be able to stir them when the syrup is boiling without having it slop over the side. Also, overcrowded walnuts tend to break more and you want the walnuts to stay whole. My big spaghetti pot is big enough to do 3 lbs at a time but that's pushing it. If you want to make a total of 5 lbs of nuts, you're better off boiling up 2 batches.
Set the pot over medium high heat and stir frequently (but carefully) once it gets bubbly. Keep stirring until the syrup gets really thick and then -- suddenly! -- the bottom of the pot is dry when you scrape it with the spoon, and all the nuts are covered in sugar. They will be gritty, not candied, because the syrup doesn't get to the temperature you need for hard candy. Spread the nuts out in a single layer on a big pan. You'll need to separate them once they cool down a little. Let them cool completely but don't let them sit around too long or they'll pick up moisture. Overnight is OK if it's dry.
Fill your fryer with oil (canola, vegetable, or peanut oil all work OK) to the fill line and heat it to 375 degrees. Fill the basket to the fill line and submerge the nuts in the oil. Shake them around gently to keep them from sticking. When the walnuts start to brown and look a little shiny, pull the basket halfway out and shake VERY GENTLY to drain off as much of the oil as possible. Watch them carefully -- this only takes a couple minutes. If they're a little undercooked, they'll be gritty. If they're a little overcooked, they'll have a slightly burnt taste, which a lot of people actually prefer. If you're working with small batches, the later batches will cook faster because of the layer of burnt sugar that builds up on the bottom of the fryer.
Dump the fried walnuts onto a jelly roll pan. Don't line the pan with paper towels or anything, because they'll stick like a sumbitch. Working fast while they're still hot, push them apart with the back of a big spoon with one hand while sprinkling them with a salt shaker with the other hand. After a couple minutes, I usually transfer to walnuts to another pan so they cool faster.
Once they're cool enough to touch, I separate the stuck ones with my fingers. When the oil cools off and you pour it out into a jar to use again the next time you fry walnuts (or faschnachts, but take it from me, DO NOT use walnut/faschnacht oil for smelts, much less smelt oil for walnuts or faschnachts), don't forget to scoop out the fried sugar and drain it on paper towels (it won't stick, because it's cool by then) and crush it up to use on ice cream because it's like getting a sundae for free. That's it. Everybody really loves these. Almost everybody, anyway.
