Place bones, skirt and radish in a large pot.
Bring to boil and sinner ar a low heat. Skim the stock from time to time.
Dry fry the cinnamon, ginger and shallots (or if available cook over a flame).
take the skin off the shallots and crush the shallots and ginger slightly. Dry fry the star anise.
All ginger, shallots, cinnamon and anise to the broth. After 5 minutes take out the star anise and cinnamon (if you leave it to long it will give the stock a "bark" flavour.
Season with black pepper and 2 tbs of fish sauce.
Simmer for around an hour.
Set the beef skirt aside to cool. Then slice finely across the grain - this will be used for serving.
Taste the broth, it should feel slightly over-salty as the lime juice, bean sprouts and noodles will absorb some of the saltiness.
Soak the dry rice noodles in hot water for 15 minutes. Then cook in boiling water over high heat for about 45-60 seconds until soft. drain well and place in bowls.
Slice shallots finely
Cover with 50% water and 50% vinegar
Add salt and sugar. Mix and leave till needed
Top the noodles with 8-10 slices of the beef skirt and 5 thinly sliced raw beef tenderloin poached in the boiling broth. Sprinkle with chopped green onions. Cover with broth.
Add 4 - 5 slices of pickled red shallots and serve with a side of red chillies, Thai basil, bean sprouts and lime.