Rinse pork ribs and drain well.
In a pot over medium heat, combine pork and enough water to cover. Bring to a boil, skimming scum that accumulates on top.
Once broth clears, add tomatoes, onion, and fish sauce. Lower heat and simmer for about 1 to 1 1/2 hours or until meat is tender, adding more water as necessary to maintain about 8 cups.
Add gabi and cook for about 4 to 6 minutes or until tender.
Add chili peppers and radish. Continue to simmer for about 2 to 3 minutes.
Add long beans. Continue to cook for about 2 minutes.
Add eggplant and okra and cook for another 1 to 2 minutes.
If using packaged tamarind base, add to the pot and stir until completely dissolved.
Season with salt and pepper to taste.
Add bok choy and continue to cook for about 1 minute. Serve hot.