Peel the shrimps (leaving the tail shell on) and make small incisions on the shrimps to straighten them.
Cut the lotus root into slices and slice the sweet potato diagonally. Place the cut pieces into a bowl of water to prevent oxidation.
In a bowl, sift the plain flour.
In another bowl, pour in the iced water and crack in an egg. Whisk until properly mixed and discard the foam on the surface.
Pour half of the egg mixture into the bowl of sifted plain flour. With a chopstick, mix using a figure-8 motion until combined, then pour in the rest of the egg mixture and mix until the batter is just combined. Don’t over mix because you want the batter to be light and airy, a few lumps in the mixture is okay. Place the bowl of batter in a bowl of ice to keep the batter cold at all time. Note: If you’re using tempura flour, omit the egg and just pour the iced water into the tempura flour and mix using the same figure-8 motion.
Pat dry the tempura ingredients with a paper towel.
Coat the shrimps and squid rings lightly with potato starch. This will help them to adhere better to the tempura batter.
Heat up the vegetable oil. Once the oil is ready, fry the ingredients in batches (do not overcrowd to maintain the oil temperature). Fry until golden brown, the frying time for each ingredient will differ. Note: Only dip the ingredients in the batter right before frying them.
In a large bowl, add in sweet soy sauce, sugar, shrimp paste and sambal belacan. Mix until combined. Reserve some for garnishing.
Add in the remaining Rojak ingredients and mix until well-combined.
Plate the rojak with the tempura as desired and enjoy!