Pre-heat oven to 180-200 degrees and chop the pumpkin into cubes, place on a baking tray and drizzle extra olive oil and roast until soft and crispy (approx 20-25 mins). Add the walnuts for the last few minutes to lightly roast.
Slice the chicken breast into strips and heat a frying pan or grill and cook for approx 10 minutes, turning and until thoroughly cooked.
Once chicken and pumpkin are cooked, add to a bowl with baby spinach, avocado, sliced apple, red onion. Once all ingredients are in a bowl drizzle with balsamic vinegar and serve.