Bring a medium saucepan of water to the boil for the noodles. Thinly slice the cabbage. Halve the carrot lengthwise and thinly slice. Thinly slice the spring onion, keeping the white and green parts separate.
Step 2 — Cook chicken
DOUBLE THE CHICKEN OPTION Combine the cornflour and Chinese barbecue seasoning in a bowl and season with salt and pepper. Dust the chicken with the cornflour mixture and shake off the excess. Heat 1 tbs oil in a large deep frypan over medium-high heat. Cook the chicken for 5-6 mins each side until cooked through. Remove from the pan. Wipe the pan clean and reserve.
Step 3 — Make sauce
While the chicken is cooking, combine the kecap manis, 1 tbs white vinegar, 1 tbs soy sauce and 2 tsp sugar in a bowl.
Step 4 — Cook noodles
Cook the noodles in the pan of boiling water for 8 mins or until tender. Drain, then rinse under cold water to prevent the noodles from sticking.
Step 5 — Stir-fry vegetables
Heat 1 tbs oil in the reserved pan over high heat. Stir-fry the cabbage and carrot for 3 mins or until just tender. Add the white part of the spring onion and stir-fry for 1 min.
Step 6 — Add noodles and serve
Add the noodles, sauce and spinach to the vegetables and cook, stirring, for 1-2 mins until heated through. Remove from the heat. Slice the chicken. Divide the noodle stir-fry and chicken among bowls. Scatter with the remaining spring onion to serve.