Place the kale in a large mixing bowl and drizzle with half of the lemon juice, then massage the leaves firmly with your hands for 2 minutes until they become dark green and tender.
Add the fresh spinach to the bowl with the massaged kale and toss lightly to combine.
Finely chop the broccoli florets, red bell pepper, and cucumber into small, uniform pieces and add them to the bed of greens.
In a separate small glass jar or bowl, whisk together the nutritional yeast, olive oil, remaining lemon juice, apple cider vinegar, and spirulina powder until the mixture forms a thick, creamy dressing.
Season the dressing with the sea salt and black pepper, adjusting the whisking speed to ensure the spirulina is fully incorporated without clumps.
Pour the citrus-spirulina vinaigrette over the salad and use tongs to toss thoroughly, ensuring every vegetable is well-coated in the savory, high-protein sauce.
Serve immediately in a chilled bowl for maximum freshness and crunch.