Preheat the oven to 170°C /gas 5. Juice all the limes into a bowl and place the lime halves into the chicken cavity along with the whole garlic, half the chilli, half the ginger and the coriander stalks. Transfer the chicken to a roasting dish and cook in the oven for 1 hr.
Meanwhile, make the sticky glaze. Add the rest of the garlic, chilli, ginger, brown sugar and fish sauce to the lime juice and use a hand blender to pulse until smooth. Add to a small saucepan and heat to reduce until thick enough to coat the chicken.
After the chicken has been in the oven for 1 hr, pour some water into the bottom of the tin. Pour half the glaze over the chicken and put back in the oven to roast for a further 45 mins covering with foil if necessary. When cooked, leave to one side to rest.
Pour the juice from the roasting tray, removing the fat, into the remaining glaze and pour into a small saucepan. Simmer over a low heat and taste. Add more sugar or fish sauce if needed.
Serve the chicken with the cucumber, spring onions and coriander, noodles and the reduced gravy.