Tom yum spaghetti

Remove the centre rib from the kaffir lime leaves and chop finely.

Pound the lemongrass, galangal, Thai chilies and lime leaves in a mortar until no big chunks remain; it need not be smooth.

Pat the shrimp dry on paper towels, sear them on their own, and take them out.

Drop the spaghetti into boiling water and set a timer for one minute less than the package says.

Saute the onions in the unwashed shrimp pan until they start to turn translucent.

Add the shimeji mushrooms and season with a little fish sauce.

Turn the heat down, add the tom yum herb paste and toss briefly.

Add the whole tomatoes, lower the heat, and break them up.

Stir in the chili paste and season with fish sauce; reduce the sauce a little, turning the heat off if it is ready before the pasta.

Move the pasta, undrained, straight into the sauce; turn the heat back on and toss for one minute, adding water if a saucier result is wanted.

Return the shrimp, toss, turn the heat off, and finish with lime juice and cilantro.

Plate, spreading the mushrooms and shrimp that sink to the bottom evenly; top with grated parmesan if wanted and plenty of cilantro.