Let me take you on a food walking experience through Hanoi Old Quarter. We will visit different local food shops and starting with small pieces of each dish and finishing with Hanoi train street. You'll see train cross in front of you.
NOTE for vegetarian or vegan: we'll eat at local shop (where meat and vegetables are optional, using the same cooking pot), so tofu/mushroom is unavailable, will be onion/bean sprout/vegetable. It will not diverse like "specific vegan restaurant".