Individually cut pork baby back ribs and pre-boil for 5-10 min in water. Drain and rinse the meat.
Slice onions, mince garlic, cut roma tomatoes in quarters lengthwise. Rinse baby bok choy, cut off about 1/2 inch of the stems.
Add cooking oil. Saute onions and garlic on medium heat until translucent.
Mix in pork meat, fish sauce, and black pepper.
Add water, bring to a boil, then reduce to back to medium-high heat for 20 minutes.
Mix in tamarind concentrate and extra salt and/or fish sauce to taste.
Lastly, add roma tomatoes and baby bok choy. Cook for the last 10 minutes.