Spaghetti flavoured with soy sauce and butter is a perfect example of fusion food done right. Based on a recipe first published on my mother's website, RecipeTin Japan, this dish is found all over Japan.
8 dried shiitake mushrooms
200g dried spaghetti or linguine
45g ghee (see note)
1 large garlic clove, finely sliced
2 tbsp Japanese soy sauce
1 tbsp mirin
1½ tbsp chopped chives, optional
¼ cup loosely packed, toasted and finely julienned nori strips, optional (see note)
1. Shiitake mushrooms: Soak mushrooms in plenty of boiling water for 30 minutes or until rehydrated. Drain, squeeze excess water out, discard stalks then slice caps into 0.5cm slices.
2. Cook pasta: Bring a large pot of water to the boil with 2 teaspoons of salt. Add pasta and cook according to packet directions, minus 1 minute.
3. Sauce: When the pasta is halfway through cooking, start the sauce. Melt ghee (or butter) in a large, deep frypan over medium heat. Add the garlic and let it sizzle briefly (30 seconds) without colouring. Add the mushrooms and toss in the butter for 30 seconds.
4. Toss pasta in sauce: Using tongs, transfer the cooked spaghetti directly into the frypan, dragging with it any water still clinging to the pasta. Add the soy sauce and mirin plus ¼ cup of the pasta cooking water. Toss the pasta over medium-low heat for about 1 minute until almost all the liquid has been absorbed but the pasta is still slick. Add one final tablespoon of pasta water and toss again.
5. Divide pasta among two bowls and garnish with a sprinkle of chives, if using, and top with a pile of nori strips.
Ghee (clarified butter) is butter without the water and milk solids, which means you can store it in the pantry rather than the fridge. It has a more intense flavour than run-of-the-mill butter but you can absolutely use butter if you don't have any ghee.
As well as bringing out the flavour, toasting the nori makes it more brittle and easier to slice. To get this quantity of nori you only need a single sheet about 20cm x 10cm. To toast, hold the sheet with tongs and pass over an open flame half a dozen times until crisp. Divide sheet into four even strips (fold and tear or use scissors). Stack strips and slice very finely with a sharp knife.