Place chicken thighs in a stock pot and cover with water or chicken broth. Add chicken bouillon cube if using water, and bring to a boil over medium high heat.
Add garlic, ginger, sugar, sesame oil, and soy sauce. Cover, and bring to a vigorous simmer on medium heat.
Once chicken has cooked through (approximately 10-15 minutes) turn heat to low and remove chicken from the pot. Place on a cutting board to remove from bones and shred into thin pieces. Add shredded chicken back into pot and toss the bones.
Break up green onion and add into pot along with vermicelli rice noodles.
Season with salt and pepper to taste.