Soak rice noodles in warm water for 30 minutes. Drained and set aside.
While noodles are soaking, ground lemongrass, galangal and thai chillies together in a pestle and mortar. An alternative is using a blender. The technique is to turn on the blender first and slowly add each ingredient. Add a tablespoon of water to ground the herbs faster. Set aside.
Heat wok on high heat. Add half of oil. Saute garlic, shallots, green onions (white part) for 3 minutes.
Mix in ground herb mixture and dried shrimp. Cook for 2 minutes.
Add in the chicken and shrimp. Toss for 1 minute.
Add carrots. Turn heat to medium and cover. Cook for 5 minutes.
Pour in rest of oil, water, fish sauce, lime juice, and peanut butter as well as zucchini. Simmer for 10 minutes to thicken.
As vegetables cook thoroughly, gradually toss in rice noodles. Make sure to coat noodle with sauce as you add in more. Sprinkle the cilantro.
Season with salt and pepper.
Pour in egg and toss continually until bits of scramble is visible. Turn off heat.
Serve in bowl. Garnished with lime wedge, green onions (green parts), toasted garlic, cilantro and chicharones.