Preheat the oven to 200c. Place the oxtail, beef bones, 4 shallots (keep one for serving), and ingredients mentioned in step 1 into a roasting pan . Bake for approx.20min .
Place the ingredients except apple into a large deep pot . Fill up with the water and bring to a boil . Simmer over medium low heat about an hour , add the apple in and bring to boil again , simmer over medium low heat for another hour . Turn off the heat and let cool a bit , remove the oil and ingredients and bring broth back to a boil .
Slice raw beef tenderloin.
Add fish sauce into a bowl, then rice noodles, mungbean sprouts, Thai basil , mint , chive , shallot, cilantro, top with beef and chilies .
Pour the boiling broth into your bowl . Serve with lime juice . Taste so good , enjoy!