Prepare the daikon: Rinse and scrub the daikon. Use a vegetable peeler to peel away the outer layer skin. Make a small slice to trim away the tip ends. Dice it into rounds, about 0.5-inch (1.27 cm) thickness then stack a few rounds and slice them into half moon shape.
Prepare carrot: Do the same with the carrot: rinse, peel away the outer layer, slice into 0.5-inch thickness rounds.
Saute aromatics: In a large 4-quart size soup pot, saute the ginger and white scallion parts with 1 tbsp oil over medium heat until fragrant, about 1.5 minutes.
Add the daikon, carrots, and stock. Cover with a lid. If the lid doesn’t have an air venting hole, leave the cover slightly ajar to prevent the soup from spilling over.
Simmer daikon: Simmer the soup over medium heat until you can easily poke through the radish with a chopstick without much resistance, about 15-20 minutes. To tell when the daikon is cooked through, besides inserting a chopstick, the daikon color also turns from pale white to a more translucent color yet the texture is still firm and not mushy.
Taste & Season: Taste the broth and season with salt, sesame oil, oyster sauce, and white pepper. Taste and adjust.
Garnish & Serve: Garnish with green scallion parts. Ladle the soup to individual serving bowls. Serve hot.
Storage & Reheating: Store the soup in a sealed container in the fridge for 4-5 days. When reheating, use the stovetop over medium heat or a microwave until it's warmed through. You’ll notice the daikon turns more translucent with each reheating, and the flavors become even milder and naturally sweet.
Daikon Soup Flavor Profile: This soup is light, aromatic, and subtly sweet—like a comforting home-cooked meal straight from your mother’s kitchen.
Daikon substitute for soup: White turnips can replace daikon in soups, especially in hearty broths. They have a slightly spicier, earthier taste compared to daikon's mild sweetness. For a milder flavor, soak the slices in room temperature water for a few hours before adding them to your soup to reduce their spiciness.