Sauté butter, green onion, garlic, and ginger in the bottom of your dutch oven until the green onion starts to soften. Should just be 2-3 minutes following the butter melting completely.
Add broth, miso, fish sauce, soy sauce and chili sauce to onion mixture.
Stir until mixed completely.
Add noodles and simmer until the noodles have cooked completely (should be less than 5 minutes once the pot is boiling.
Add ground beef, sesame seeds, oyster mushrooms and spinach leaves in each person's bowl.
Enjoy!