Samlor Machu Kroeung (សម្លម្ជូរគ្រឿង) — Cambodian Sour Kroeung Beef Soup

• 3lemongrass stalks (tender lower 12 cm only, thinly sliced)
• 30 ggalangal (peeled and thinly sliced)
• 20 gfresh turmeric (peeled and chopped)
• 4 leafkaffir lime leaves (center ribs removed and leaves finely shredded)
• 5 clovegarlic
• 3shallots (peeled and sliced)
• 4 gfine sea salt
• 900 gbeef short ribs (cut across the bone into 5 cm pieces)
• 30 mlneutral oil
• 1.8 lwater
• 35 gprahok (fermented fish paste, finely chopped)
• 55 gtamarind paste (seedless, unsweetened)
• 30 mlfish sauce
• 12 gpalm sugar
• 3Asian eggplants (cut into 3 cm chunks)
• 150 ggreen beans (trimmed and cut into 5 cm lengths)
• 200 gwater spinach (also called morning glory, cut into 6 cm lengths)
• 12 gfresh culantro (thinly sliced)
• 15 mllime juice
• 6 cupcooked jasmine rice

Instructions

1. 1

   Make the yellow kroeung paste by pounding the lemongrass, galangal, turmeric, kaffir lime leaves, garlic, shallots, and 4 g salt in a mortar until the mixture becomes damp, fibrous, and aromatic. If using a food processor, pulse in short bursts and scrape often, adding 15 ml water only if the blades cannot catch the aromatics.

2. 2

   Pat the beef short ribs dry with a clean towel so they brown instead of steaming. Heat the oil in a heavy pot over medium-high heat, add the beef in one layer, and brown it for 8 minutes, turning the pieces until the edges are deeply colored.

3. 3

   Lower the heat to medium and add all of the kroeung paste to the pot. Fry it with the beef for 5 minutes, stirring constantly, until the lemongrass smells toasted and the oil turns golden from the turmeric.

4. 4

   Add 1.8 l water and scrape the bottom of the pot to dissolve the browned bits. Stir the prahok into 120 ml of the hot broth in a small bowl, mash it smooth with a spoon, and return it to the pot so the fermented fish flavor disperses evenly.

5. 5

   Bring the soup to a gentle boil, then reduce the heat to maintain a steady simmer. Cover the pot partly and cook for 70 minutes, skimming foam from the surface during the first 15 minutes, until the beef is tender but still holds its shape.

6. 6

   Stir in the tamarind paste, fish sauce, and palm sugar until fully dissolved. Simmer for 5 minutes, then taste the broth for balance: it should be clearly sour, savory from prahok, lightly sweet, and fragrant with kroeung.

7. 7

   Add the eggplant and green beans and simmer for 10 minutes, keeping the vegetables intact rather than mushy. Add the water spinach and cook for 2 minutes more, just until the stems soften and the leaves turn glossy green.

8. 8

   Turn off the heat and stir in the culantro and lime juice. Rest the samlor for 5 minutes before serving so the sourness settles into the broth and the beef absorbs the final seasoning.

9. 9

   Ladle the soup into deep bowls with pieces of beef, eggplant, green beans, and water spinach in each serving. Serve immediately with cooked jasmine rice, letting diners spoon the hot sour broth over the rice at the table.