Peel daikon and taro (if you are using it). Slice them as well as the bok choy, onion, and tomato. Slice the large mild pepper in half once.
In a large pot over medium heat, pour water according do your sinigang mix instructions. Also add the sinigang mix. My mix called for 2 liters (8 cups) but I like mine more sour so I only added 6 cups. Add the onion and tomato. Cook for about 5 minutes or just before the soup begins to boil.
Add the daikon radish, taro (if available), and mild pepper. Let this boil and then turn the heat to low so the radish and taro will soften. This will take about 15 min. You can test the readiness of the radish using a fork or chopstick.
Once the veggies are cooked to your liking, add the shrimp and bok choy. Let the shrimp cook. This should take 5 to 10 minutes.
Remove from heat once the shrimp is finished cooking. Serve with rice and enjoy!