In a large pot, high heat, boil salted water. Cook pasta. After that, put pasta in a cold water and let it cool.
Cut bitter melon. In a medium bowl put bitter melon and pinch salt and mix them together and give it massage. This way, the bitterness will get mild. Leave it for 5 minutes
In a medium pot, boil water and cook bitter melon for 5 minutes. (If you like to leave bitter flavor, you can only boil for 2 minutes). In a large bowl, rest the cooked bitter melon in ice cold water.
Slice onion and put it in hot water for 2 minutes to remove the bitterness. Put onion in the same ice cold water as the bitter melon is resting.
Cut daikon radish in tooth pick shape and soak in the cold water for 2 minutes.
Then put it in the same ice cold water.
Cut cucumbers into the same shape as the bitter melon.
Smash sour plum into paste.
In a small bowl, mix sour plum, tuna,olive oil and mentsuyu.
Drain vegetables with salad spinner and squeeze the water out from the vegetables.
In a large bowl, mix pasta and vegetables well and add the sauce.
Top with cilantro, seaweed and bonito flakes if you prefer.
