Blanch the florets of broccoli for one minute in boiling water. Drain and set aside. Chop the spring onion, removing the darkest green leaves as you go. Peel the garlic and chop it finely, then seed and chop the chillies. Get the oil really hot in a shallow pan then cook the onions and chillies until soft but not coloured, moving them quickly round the pan as you go. It will appear there is too much oil, but bear with me.
Add the minced lamb, let it colour appetisingly. It should go a rich golden colour. Add the drained broccoli. In a small bowl mix the juice of the lime with the nam pla and sugar. Tip into the hot pan, leave to sizzle briefly scraping at the gooey stickings on the bottom of the pan and stirring them in as you go. Check the seasoning - you may need a little salt - and stir in the coriander.