Using a vegetable peeler, slice the carrot and cucumber into thin ribbons, then cut these into long strips if needed.
Finely shred the red cabbage and thinly slice the onion.
Place all the vegetables into a large mixing bowl and add the pumpkin seeds.
In a small bowl or jar, whisk together the olive oil, apple cider vinegar, date syrup, salt, and pepper.
Add the chilli and garlic if using, then taste and adjust the dressing to your liking.
Pour the dressing over the salad and toss well to combine.
Leave the salad to rest for about an hour before serving so the flavours can develop.
Stir through the chopped parsley and squeeze a little lemon juice over it just before serving.