Beef Sinigang (Beef in Tamarind Broth)

Beef Sinigang (Beef in Tamarind Broth) Ingredients:
6 cups water 
3 cups stewing beef, preferably beef brisket, bone-in or beef short ribs, cut into chunks (pork, fish, shrimps or scallops may also be used) 
5 tbsp Mama Sita's Biglang Sinigang (Tamarind Paste) 
1 pc onion, quartered 
2 pcs tomato, sliced into 1" wedges 
2 pcs radish, peeled and cut into 

1/4" diagonal slices 
1 cup green leafy vegetables (like kangkong, spinach, or mustard greens) 
1 cup sitaw (long beans), cut into 
2" strips 2 pcs sili (green chili pepper) 
1 tsp patis (fish sauce)