Cook noodles to package instructions with the turmeric (for color purposes). Slightly undercook, drain, and rinse under cold water. Toss with sesame oil so they don’t dry up and stick together.
Heat oil in cast iron. The next few steps go QUICK so keep up. Add garlic, ginger, green chilis, the white parts of the green onion, and onion. Stir for 1-2 minutes.
Add carrots and bell peppers. Stir until they are mostly cooked, but still crunchy.
Whisk sauce in a small bowl: tamari, rice vinegar, chili garlic sauce, and coconut sugar. Add noodles to the pan and pour the sauce on them.
Fry the noodles for a couple minutes. Add black pepper, red chili flakes according to your liking, and spring onion greens.