Thai Spicy Sour Beef Soup

Makes 2 portions.
Boil water. Add salt, ginger or galangal, kaffir lime, lemon grass, coriander roots, shallot and beef. Skim off scum.
Make sauce:
- 2 tbsp tamarind juice (thick sauce)
- 3 tbsp fish sauce
- 1 tsp palm sugar
- Ground Thai chili
- 2 tbsp roasted rice powder
- 2 tbsp lime juice
Mix sauce well. Divide sauce in half and put it in bottom of each bowl. Pour soup and beef into the bowl with sauce. Garnish with green onions, cilantro