Bring a medium pot of salted water to a rolling boil. Cook the noodles according to package instructions until al dente, usually 6-8 minutes. Drain thoroughly, toss with a little oil to prevent sticking, and set aside.

Cut the chicken into uniform bite-sized pieces (about 1-inch chunks) if not already done. Toss the chicken pieces in a bowl with 2 tablespoons cornstarch until evenly coated with a light dusting.

Heat 2 tablespoons vegetable oil in a large skillet or wok over medium-high heat until shimmering. Add the cornstarch-coated chicken in a single layer without overcrowding. Cook for 4-5 minutes on each side until golden brown and cooked through to 165°F internal temperature. Remove chicken to a plate and set aside.

In the same skillet, add minced garlic and grated ginger. Sauté for 30-60 seconds until fragrant but not browned, watching closely to prevent burning.

Stir in soy sauce, honey, and red chili flakes if using. Cook for 2-3 minutes, stirring constantly, until the sauce thickens slightly and coats the back of a spoon. For a thicker sauce, whisk 1-2 teaspoons additional cornstarch with equal parts water and stir into the bubbling sauce.

Return the cooked chicken to the skillet and toss for about 1 minute until every piece is completely coated in the sticky sauce.

Add the cooked noodles to the skillet. Toss thoroughly for another minute until noodles are warmed through and coated in sauce. Remove from heat.

Sprinkle with chopped green onions and sesame seeds. Serve hot immediately.