Soak pancit bihon in warm water in a large bowl or bucket. Drain after 20-30 minutes or until it is tender.
Heat oil in a large wok or stockpot over medium-high heat. Saute onions and garlic, then add chicken. Cook until pale white.
Add water and soy sauce. Cover. Bring to a boil.
Add green beans and carrots. Cook for 15 minutes.
Toss in bouillon, bell pepper, ground black pepper, and salt. Cover and cook for 5 minutes.
Remove cover and taste. Add more seasonings if needed.
Add the bihon. Mix until everything is well blended and all the liquid is absorbed.
Garnish with chopped green onions and drizzle with lemon.