Warm sesame oil in a large pot over medium-high heat.
Once hot, add garlic, ginger and onion. Saute, stirring occasionally for about 5 minutes, or until the onion has developed a slight sear.
Add 1 cup of the vegetable stock to deglaze the bottom of the pot.
Add remaining 5 cups of vegetable broth and tamari and stir.
Bring to a simmer over medium heat, then reduce heat to low and cover. Simmer on low for at least 1 hour, stirring occassionally.
Taste broth and adjust seasonings as needed, adding more tamari or sesame oil if desired. Add the miso paste and whisk until combined.
When you're 30 minutes from serving, prepare toppings. Warm vegetable oil in a large skillet over medium heat. Add "chicken" and cook for about 3 minutes, until "chicken" starts to brown. Add tamari and mix in well. Cook for about 2 more minutes, then remove from heat.
Chop snap peas and bok choy, then lightly steam.
Cook noodles according to package instructions and drain well.
Strain broth twice.
To serve, divide ramen noodles between four serving bowls. Top with broth, chicken and veggies.