koreancookery1-7, Challenge 2: Why cook japchae ingredients separately

Model answer:

The japchae article says each ingredient is cooked separately, then combined with the boiled and drained noodles and seasoned with soy sauce, sugar, chopped garlic, green onions and sesame oil. It does not give a reason.

My guess (unverified): the vegetables need different times (spinach wilts in seconds, carrot and onion take minutes), so cooking them separately keeps each at the right texture and keeps the colours distinct.

Your own notes: write which vegetables took how long, and whether the noodles were still chewy at the end.