Bring a large pot of water to a boil. Crush 3 cloves of garlic and 5cm of ginger then place them into the cavity of the chicken. Tie the spring onions into a knot and place them into the chicken along with 1/2 teaspoon of salt. Carefully submerge the chicken breast side down into the water.
Bring to a boil then cover and remove from heat. Let stand covered for 40 minutes turning the chicken over half way through.
While the chicken is cooking heat the vegetable oil and 1 tablespoon of sesame oil in a large saucepan over medium heat. Fry the shallots, ginger and garlic in the oil until fragrant. Add coriander and rice then cook, stirring until toasted. Pour in chicken stock and season with salt. Bring to a boil then cover and reduce heat to low. Simmer until rice is tender and 'steam holes' appear in the surface of the rice; about 20 minutes.
When the chicken is done cooking remove it from the pot and place under cold running water to tighten the skin. Rub the outside with sesame oil and chop into pieces. Place pieces on a serving platter and garnish with coriander, spring onion, cucumber and tomato. Serve with rice.