To begin, prepare the batter by cracking a large chilled egg into a bowl. Beat it lightly, then add ice-cold water, ensuring the water is as cold as possible—this helps achieve a light, crispy texture. Whisk together but avoid over-mixing. The key here is to keep the batter cold, so set it aside in the fridge while preparing the vegetables and shrimp.

Next, sift the flour into a separate bowl. Sifting aerates the flour and prevents lumps from forming in the batter. Once sifted, keep the flour aside for when you are ready to combine it with the wet ingredients. You’ll want to keep everything cold to ensure the tempura’s signature crispiness.

Prepare the vegetables and shrimp for frying. Slice the sweet potato, zucchini, and carrot into thin, uniform pieces for even cooking. Clean and remove the stems from the shiitake mushrooms. For the shrimp, lightly score the underside to prevent them from curling during frying. Set everything on a paper towel to remove any excess moisture.

In a large, deep pan, heat vegetable oil to 340°F (170°C). Use a thermometer to maintain the right temperature—if the oil is too hot, the batter will burn; if too cold, it will absorb too much oil. While the oil heats, take out the batter from the fridge.

Quickly combine the sifted flour with the cold egg mixture. Using chopsticks or a fork, gently fold the ingredients together with minimal stirring. A few lumps are fine—it’s important not to overmix, as this ensures the batter stays light and airy. You’ll need to work quickly from this point to keep everything cold.

Begin frying the ingredients. Lightly dust each vegetable slice and shrimp with a bit of flour before dipping them into the batter—this helps the batter adhere better. Immediately place the coated pieces into the hot oil, frying only a few at a time to avoid overcrowding. Fry each piece for 2-3 minutes or until golden and crispy.

Remove the tempura from the oil using a slotted spoon and drain on paper towels to absorb excess oil. Make sure to skim off any leftover batter bits from the oil between batches to keep it clean. Continue frying the remaining ingredients in small batches.

Serve the tempura immediately for the best texture. Arrange the vegetables and shrimp on a platter, and pair them with a light soy-based dipping sauce (tentsuyu) or soy sauce. For a traditional touch, serve alongside grated daikon radish and a small bowl of salt for added seasoning. The contrast between the crisp batter and the tender ingredients inside is what makes tempura a true delight.