Jaljeera Drink (Indian Flavoured Lemonade)

1/4 cup packed chopped mint leaves (podhina)
1/4 cup packed chopped cilantro (hara dhania)
1 tablespoon chopped ginger (adrak)
1 tablespoon cumin seed dry roasted and powdered (bhuna jeera)
Pinch of asafetida (hing)
1 teaspoon salt
1 teaspoon black salt (kala Namak) available in Indian stores
3 tablespoons lemon juice
1 tablespoon tamarind seedless (imli)
2 tablespoon sugar adjust to taste
4 cups water
1 cup crushed ice