Bring a large pot of water to a boil on the stovetop. Add the noodles and cook, stirring often, until al dente (tender with a little bite). Reserve 1 cup of the starchy pasta water, then drain the noodles and rinse with cold water. Shake off any excess water, then return to the pot. Drizzle sesame oil over top and toss to coat well. Set aside.
Add all listed ingredients to a small bowl and whisk to combine well. Set aside.
Melt the butter in a large wok or skillet over medium heat. Add the garlic and cook, stirring often, until golden and fragrant, 2-3 minutes. Add the green onions and cook, stirring often, just until fragrant, 30 seconds – 1 minute longer. Add the noodles and stir fry sauce to the skillet, tossing to combine well. If things get sticky, add some of the reserved pasta water to loosen everything up. Taste and adjust seasoning as needed.
Finish the noodles with a sprinkle of finely sliced green onions and toasted sesame seeds. Serve immediately. Enjoy!
