Heat 4 cups of oil to 340℉.
Before deep frying, make sure to pat the ingredients dry with a paper towel (extra moisture will dilute the batter). Whisk the tempura batter each time before dredging the ingredients.
Coat individual slices of vegetables with batter.
Place vegetables in the pan in a single layer, without overlapping. Don't overcrowd the pan.
Deep fry at 340℉ for about 3 minutes, or until desired shade of golden brown.
Shake off excess oil and transfer to a wire rack or a plate lined with a paper towel.
Be sure to remove crumbs from the oil in between each batch.
Serve immediately with dipping sauce.