This is one of my favourite dishes. It's so flavourful and it's carb heavy :) First, this isn't totally authentic. Fish sauce plays a major role in Thai cooking. I like to substitute tamari sauce - its vegan and gluten free.
Start with wide rice noodles. Soak them in warm water until they're rubberband-like. They should be flexible and have a bit of stretch. While they're soaking, fry up some extra-firm tofu. It's not essential to fry it, but it keeps the tofu from crumbling so much. Also, fried food is delicious.
Then mix up a seasoning blend. I use: tamari, tamarind, palm sugar, a whisper of red curry paste and some coconut milk to keep it all liquid in the pan. I experimented with black soy sauce in this dish. It's basically soy sauce with molasses. It's tasty, but contains gluten. If that's a deal breaker for you, skip the black soy sauce in favour of tamari and a smidgen of molasses.
Add the seasoning and coconut milk mix to a hot pan and drop in the noodles. Stir it, jostle it, shake the pan a bit. Be sure to keep the noodles moving to prevent them from clumping. Coconut milk is high in fat and it helps keep the noodles moving.
When the rice noodles are starting to get tender, add in some chopped vegetables. I use bok choi, green onions and carrots. Continue to cook until the vege is slightly cooked - it should still have some bite; not at all mushy.
Finally, add the tofu. Adding it last will keep it from getting smashed and crumbly. Give it a final stir and plate it up with some fresh Thai basil.