Bring a large pot of salted water to boil and cook spaghetti until just tender, about 8 minutes. Drain and toss with sesame oil.
Warm vegetable oil in large skillet over medium-high heat. Add shrimp and scallions and cook, stirring, until shrimp are pink and cooked through and scallions have softened, 3 to 5 minutes.
Add spaghetti, peas and teriyaki sauce and cook, tossing to coat and heat through, about 2 minutes.
