Ingredients

• 2 pounds boneless beef shanks, cut into serving pieces
• 8 cups water
• 1 onion, peeled and quartered
• 1 tablespoon fish sauce
• 3 Roma tomatoes, chopped
• 1 pound (about 10 to 12 pieces) large ripe and semi-ripe guavas, peeled, quartered, and seeded
• salt and pepper to taste
• 1 small bunch kangkong