scallions and ginger
In a small bowl combine, scallions, ginger, sugar, soy sauce, rice vinegar, cayenne pepper, and a pinch of salt. Mix to combine.
cook the noodles
In a pot of boiling water, cook the noodles for 4 minutes or according to the package instructions. Reserve 60ml (1/4 cup) of the cooking water, then drain.
pan fry the shrimp
Place a non-stick pan over medium-high heat. Add the sesame oil. Pan-fry shrimp for 2 - 3 minutes. Transfer the shrimp to a plate. Pour the remaining canola oil into the pan. Cook the oil until it's hot, then remove from the heat. Check the oil temperature. It should be 110°C / 225°F.
Pour the hot oil over the scallions mixture in a bowl. Leave until it stops sizzling, then stir well. Add the drained noodles to the pan where the oil was heating. Add the scallion ginger mixture, cooked shrimp, and some reserved cooking water. Stir well. Divide between two bowls and serve. Sprinkle with sesame seeds and serve with lime wedges.