Clean the shrimps. In a large saucepan, heat half of the olive oil, pour onion, cook over low heat and stir for about 5 minutes. Then add the wine. Bring to a boil, cook over medium heat for another 10 minutes.
Boil spaghetti in the salted water until cooked.
Meanwhile, heat up the remaining olive oil in a large frying pan, put the shrimps, cook for about 2-3 minutes, until pink color appears on all sides. Add the garlic, cook for about 1 minute. Season the shrimps with salt and pepper shrimps according to your taste.
Place the spaghetti into a bowl (you can serve it in the form of nests according to the Japanese traditions), lay the shrimps on top and decorate with the slices of fresh cucumber.