Set a large soup pot over medium heat. Add the neutral oil and let it warm for about 30 seconds.

Add the scallion whites and the sliced celery to the pot. Cook, stirring often, until the celery starts to soften, about 3 minutes.

Add the sliced garlic to the pot. Cook, stirring, until it smells fragrant and no longer looks raw, about 30 seconds.

Put the chopped tomatoes into the pot. Cook them for 5 to 6 minutes, stirring and pressing them with a spoon, until they collapse and release plenty of juice.

Stir 2 tablespoons of the tamari into the tomatoes.

Pour the water into the pot and raise the heat to high.

Bring the soup to a boil. Once it boils, lower the heat so the liquid stays at a steady simmer and cook for 5 minutes.

Add the bok choy stems to the pot. Simmer until they start to lose their raw crunch, about 2 minutes.

Add the dried rice noodles to the pot. Push them down into the broth so they soften evenly.

Cook the noodles for 2 minutes, stirring gently every 30 seconds so they do not clump together.

Add the bok choy leaves to the pot. Cook for 1 to 2 minutes, until the leaves wilt and the noodles are tender.

Lower the heat to low. Carefully slide the tofu cubes into the pot so they keep their shape.