Goma Hiyashi Chūka

Name: Goma Hiyashi Chūka
Ingredients: 220 grams ramen noodles - fresh; 26 grams sesame seeds - toasted (about 3 tablespoons); 2 tablespoons water; 2 tablespoons soy sauce; 1 1/2 tablespoons tahini; 1 1/2 tablespoons rice vinegar; 2 teaspoons toasted sesame oil; 1 teaspoon sugar - unrefined; 1/8 teaspoon salt; 1/2 teaspoon chili sesame oil (optional); 1 extra large egg; 1/16 teaspoon salt; 1/4 teaspoon sugar - granulated; 85 grams cucumber - Japanese or Lebanese (1 cucumber); 85 grams imitation crab (10 sticks); 85 grams tomato (1 medium tomato)