Toast & prep: In a dry skillet over medium heat, toast chickpea flour 2–3 min until nutty; whisk with 3 tbsp water to make a smooth slurry. Set aside.
Build curry: Heat oil in a saucepan (medium). Sauté onion 5–6 min until lightly golden. Add garlic and ginger; cook 30 sec. Stir in turmeric, paprika, chili powder, and curry powder; cook 20–30 sec until fragrant.
Cook chicken: Add chicken; sear 2–3 min. Add fish sauce and stock; simmer gently 10–12 min until tender.
Thicken: Stir in coconut milk (if using), then the chickpea-flour slurry. Simmer 2–4 min until glossy and spoon-coating. Salt to taste. Spoon off 1–2 tbsp of the orange curry oil and reserve for tossing.
Noodles: Boil noodles just until tender and bouncy; drain very well.
Toss: In a large bowl, combine noodles with ¾–1 cup curry sauce, 1–2 tbsp reserved curry oil, a squeeze of lime, and a drizzle of chili oil. Adjust salt/lime/heat.
Top & serve: Add eggs, red onion, cilantro, fried garlic, and peanuts. Serve extra curry and lime on the side.