I just did my first tempura batch ever tonight. It was perfect. Here
is what I learned:

- a 450 degree candy thermometer + a 5-qt pot are just as good as my
Roto Deep Fryer - and only cost $10 or so
- use vegetable oil - not corn or other stuff
- pre-cook hard vegies like potatos, pumpkin, carrot, etc...
- use the oven to ROAST veggies that need pre-cooking, NOT a steamer or
boiling water; water is BAD for frying food
- use a pot with a tight fitting lid
- a stainless steel skimmer (search amazon.com for an excellent
example) is the BEST way to remove food from the hot oil
- salt the food the moment it is out of the oil - very important for
proper flavor
- add a bit of salt & pepper to the food BEFORE you dip it into the
tempura batter; other seasonings, like Emerils Spice, etc... are AWSOME
also; basic salt & pepper are equally awsome
- oriental dipping sauce for tempura can be anything, BUT
ponzu/terriaki/water mix is my favorite
- use ICE cold water or sparkling water with the box of tempura batter;
did I say ice water?

The box of tempura batter has a basic recipe that rocks. I used
raw/peeled/deveined shrimp, scallops, mushrooms, roasted potato (not
cooked all the way, just 2/3 cooked), onion rings, and zuchinni. Have
fun!