To make the broth, place a pot over a medium heat on the stove and add all stock ingredients. Simmer for 15 minutes and taste (balance the flavours if necessary). Remove all hard pieces from the broth.
To the pot, add the noodles, broccoli, mushrooms and seaweed then cook for three minutes. Add the spinach and stir through until wilted.
To serve, pour all ingredients from the pot into a bowl. Top with the raw beef and coriander. The beef will cook on its own when stirred through the noodles and broth.