Heat the curry paste in hot oil, add the garlic and ginger and fry the chicken breast pieces on all sides, then deglaze with the stock. Add coconut milk and orange juice. Add the cumin, curry powder, turmeric and coriander as well as the lemongrass stalks (whole), bring to the boil and simmer for about 10-15 minutes. Add lemon juice and season to taste briefly.
Add vegetables (bell peppers, mushrooms, mung bean sprouts) and rice noodles and let simmer, attention: most rice noodles do not take longer than 5 minutes. The vegetables should still be crisp. Remove the lemongrass stalks and serve the soup in bowls.