A photo like it (tom yum noodles in Bangkok) · Sakurai Midori (CC BY 2.5) via Wikimedia Commons · source
Bangkok's favorite noodle lunch: hot, sour, sweet and salty at once, with ground pork, prawns and crushed peanuts. Dry (haeng) or in soup; this is the soup.
150 g (5 oz) ground pork, 6 raw prawns, 4 fish balls (optional)
To season: 2 tbsp fish sauce, 2 tbsp lime juice, 1 tbsp sugar, 1 tbsp roasted chili paste (nam prik pao), 1-2 tsp chili flakes, 2 tbsp evaporated milk (optional, for the creamy kind)
150 g (5 oz) thin rice noodles or egg noodles
To top: 2 tbsp crushed roasted peanuts, bean sprouts, sliced scallions and cilantro, fried garlic
How to make it
Broth (10 min): Simmer the stock with the lemongrass, galangal and lime leaves 8 minutes.
Meat (5 min): Drop in the pork in small pinches, then the prawns and fish balls, and cook 3 minutes.
Season (2 min): Off the heat, stir in the fish sauce, lime, sugar, chili paste, chili flakes and evaporated milk. Taste: sour, then hot, then salt, then sweet; fix the balance.
Build (3 min): Blanch the noodles and sprouts, put in bowls, ladle over the soup with the meat, and top with peanuts, scallions, cilantro and fried garlic.
Tips
Lime juice goes in off the heat; boiling makes it bitter.
Jeh O's 'Mama' version: use 2 packs of instant noodles and add a soft egg.