This style of pasta is very popular in Japan. You can find packaged ume/shiso flavorings for pasta, but nothing beats the homemade version. The first part of this recipe consists of making sweetened ume paste called ume bishio. It is something most Japanese don't even know how to make anymore and it is a shame. It is super versatile and can be used for many recipes. It keeps forever in refrigerator too. For this recipe, you only need to use 3 T of ume bishio and you can keep the rest in the refrigerator for later use. This sauce will only barely coat the spaghetti and is not meant as a thick sauce such as marinara and more like Japanese style pesto sauce.
- For Ume Paste/Ume Bishio:.
- First soak umeboshi in water for 3-4 hours to remove some of the saltiness. It is best to change water every hour.
- Remove umeboshi pits by using a small knife. Mince very, very finely until paste or use a food processor and pulse until it is a smooth paste.
- Using a small pan, combine ume paste, sugar, and mirin over low heat. Turn down to simmer and stir frequently. It is done when the paste becomes shiny. This usually takes about 10-13 minutes.It will take on a beautiful shiny appearance and color.
- Remove from heat.
- Gather shiso leaves and roll into pencil shape. Slice thinly into chiffonade.
- Place butter in a large bowl and beat until creamy. Combine 3 T ume paste and mix well.
- Boil spaghetti until al dente and drain. Mix spaghetti with butter/ume mixture along with thinly sliced shiso in the bowl.
- Serve either hot or at room temperature.