Prepare the radish by peeling and slicing it into thin pieces, then dicing these slices into triangle shapes.

Heat a large pot over medium-high heat and add a splash of sesame oil. Sauté the diced radish for 2-3 minutes until slightly translucent.

Add in the sliced green onions and continue sautéing for another 2 minutes until fragrant.

Stir in a piece of kombu, dried shiitake mushrooms, and minced garlic. Pour in water or vegetable broth, cover ingredients, and bring to a gentle boil. Simmer for about 12-15 minutes.

After the radish has softened, season with gluten-free soy sauce or coconut aminos, and salt to taste. Let simmer for an additional 3 minutes.

Ladle the soup into bowls, garnishing with sesame seeds and fresh green onion slices.