I haven't had a chance to test this recipe yet, but it looks promising so I'm putting it up here so it's available to reference when making vegan versions of recipes that call for fish sauce. I think the combination of mushrooms, konbu, and tamari/soy should work quite well!

Vegan Fish Sauce Substitute

Slighlty adapted from Clean, Green, Simple

Ingredients

• 4 c. water
• 1/2 c. dried shiitake mushrooms
• 1/4 c. tamari (or dark soy sauce)
• 2 sheets konbu, each 10cm by 10cm
• 2 1/2 Tbsp. coarse sea salt
• 1/8 tsp. garlic powder

Directions

1. Combine all ingredients in a pot and bring to a boil.
2. Simmer, uncovered, until volume has reduced by about half.
3. Strain, cool, and store in a glass jar in the fridge.
4. Use as a 1:1 substitute for fish sauce.