2 pounds pork spare ribs – cut into 2–3-inch pieces
10 cups water
10 ounces onion – quartered
12 ounces tomato – quartered
12 ounces taro (gabi) – peeled and cut into 1.5-inch chunks
12 ounces daikon radish – peeled and sliced into 0.5-inch half-moons
10 ounces eggplant – cut into 1.5-inch pieces
0.5 cup tamarind concentrate
2 tbsp fish sauce
6 ounces yardlong beans (sitaw) – cut into 2-inch lengths
2 pieces long green chili peppers – slit lengthwise
4 ounces water spinach (kangkong) – leaves and tender stems, cut into 2-inch pieces
1.5 tsp kosher salt
Instructions
Combine the pork spare ribs, water, onion, and tomatoes in a large pot and bring to a boil over high heat, 8–10 minutes, skimming off any foam.
Reduce to a gentle simmer, partially cover, and cook until the pork is tender but not falling apart, 45–60 minutes, skimming as needed.
Add the taro (gabi) and simmer until beginning to soften and lightly thicken the broth, 10–12 minutes.
Add the daikon radish and eggplant and simmer until just tender, 8–10 minutes.
Stir in the tamarind concentrate and fish sauce, then add the yardlong beans and long green chili peppers. Simmer until the beans are crisp-tender and the broth tastes bright-sour, 4–6 minutes.
Stir in the water spinach and cook until just wilted, 1–2 minutes.
Off the heat, season with kosher salt to taste. Ladle into bowls and serve hot.