Tomato and lime bring a pleasing sourness to fiery sambal and fragrant lemongrass for this soup inspired by the Thai classic, tom yum. Spice and acid work beautifully with bites of silky pork dumplings to balance the bright flavours for a quick and robust weeknight dinner.
Bruise lemongrass stalk and roughly chop into large pieces. Peel and bruise garlic.
Place lemongrass, garlic, lime leaves and stock cube in a saucepan with 625ml (2½ cups) water. Place over high heat and bring to the boil, stirring, to dissolve stock cubes.
Add sambal oelek and cherry tomatoes and reduce heat to medium. Cook for 6–8 minutes or until tomatoes begin to break down.
Meanwhile, bring a separate saucepan of water to the boil. Add dumplings and cook for 7–8 minutes or until cooked through.
Add oyster mushrooms to soup and simmer for 1-2 minutes to lightly cook. Juice lime and add to soup with fish sauce and sugar. You may like to add a little more sugar or salt to taste, if needed.
Remove lemongrass and lime leaves from soup and discard. Divide dumplings between serving bowls. Ladle over hot and sour soup to serve.