Start by combining the ingredients for the dressing in a bowl. Taste to check if the seasoning needs to be adjusted.
Preheat a nonstick pan over medium heat. Dry roast the pumpkin seeds until golden brown.
Meanwhile slice the red lettuce and green cabbage into smaller pieces.
Slice the red cabbage and brussels sprouts thinly, preferably using a mandolin.
Add lettuce, green kale, red cabbage and brussel sprouts to a big bowl.
Separate the grapefruit, add to the bowl.
Add the dry roasted sesame seeds and furikake seasoning to the salad.
Pour the dressing over the salad, mix to combine, making sure all parts of the salad are covered with the dressing.