You want to see the outside get crispy, and pieces of batter kind of flail off of it, like wavy, radical-looking arms. And it should be rare in the center—cool in the center—cause it's raw in the core and crispy and hot on the outside. MH: At the restaurant, you serve one or two pieces of tempura at a time. AY: Each piece is served one by one because the more time that lapses, the less crispy the thin tempura batter will be. If you don’t have a kitchen counter to eat at, bring small batches to the table for them to eat, and try to eat very quickly.