Peal and cut the onion in half, then slice thinly. Cut the carrot into sticks and put them aside. Cut the shiso leaves thinly. Cut the sweet potato into sticks same as the carrot.
Place the sliced vegetables in a bowl and coat with 2tbs flour.
Place the flour and salt in a separate bowl and pour in the water, mix them together but try not to mix them too much to avoid the batter becoming glutinous.
Add the sliced vegetables and mix them with batter, try not to over mix.
Heat oil in a deep frying pan to 170 degree.
Scoop the mixture with a radle and with a pair of chopsticks, slide the batter and vegetable mixture into the oil gently.
Deep fry the batter till golden brown on both sides.
Serve with salt or tempura dipping sauce.
*1 Nutritional value is indication only as it is difficult to culcurate acurately. Oil absorption is culcurated 10% of ingredients weight. Oil amount displayed in the ingredients list is the absorbed amount. It is required more than 50ml to deep fry.