Bring a large pot of salted water to a boil. Add spaghetti and cook according to package instructions until al dente, about 8-10 minutes. Drain and rinse briefly under cold water.

In a large skillet, heat sesame oil over medium heat until shimmering. Add minced garlic and sauté for 1-2 minutes until golden and fragrant.

If using vegetables, add them to the skillet and sauté for about 3-5 minutes until tender.

Stir in chili crisp and soy sauce, mixing everything together and cooking for 1-2 minutes until aromatic.

Add the drained spaghetti to the skillet, tossing to coat thoroughly, cooking for another 1-2 minutes.

Taste and adjust seasoning with more chili crisp or soy sauce if desired. Serve immediately, garnished with chopped green onions.