Pour water into a cooking pot. Let boil. Add chicken. Boil for 35 minutes.
Remove chicken from the pot. Let it cool down. Shred the chicken (separate meat from bones). Set the shredded meat aside.
Add annatto seeds into the pot with chicken stock. Cover the pot, boil for 5 minutes. Set aside.
Heat oil on a wide pan. Add garlic. Cook until the garlic turns golden brown in color.
Remove half of the garlic from the pan. Set it aside.
Continue cooking using the remaining garlic. Add onion and celery into the pan. Sauté until the onion softens.
Add shredded chicken. Sauté for 1 minute.
Pour the chicken stock into the pot while filtering the annatto seeds using a strainer or kitchen sieve. Let boil.
Add Knorr Chicken Cube. Stir.
Add carrot and half of the total green onions. Cook for 2 minutes.
Add bihon noodles. Cover the pan. Cook for 2 to 3 minutes. Toss noodles and continue to cook until liquid gets totally absorbed.
Season with ground black pepper and fish sauce (patis). Toss. Adjust heat to low. Cover the pan and cook for 1 ½ minutes.