These tips, however, are very useful, despite their semi-obsession with all things fennel. (via Rebecca Blood)
Here are two I'll use for sure:
Peeling Chestnuts
The hard shell of a chestnut protects the tender meat. This technique removes in one piece both the shell and the thin membrane that covers the meat. 1. Score the shell of each chestnut around its equator. Do not cut into the meat. 2. Heat chestnuts in a 400-degree oven until the shells split, about 5 to 10 minutes. Remove the nuts from the oven. As soon as they can be handled, lift off shell and membrane (they should come off together) from each half. -- Cook's Illustrated
Coring Apple Quarters
When apple quarters are cored starting at the stem end, the quarters tend to break. However, this problem does not occur if you core the quarters starting at the blossom end. -- Cook's Illustrated
