Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
In a large mixing bowl, combine the cauliflower florets and drained chickpeas with the olive oil, garlic powder, smoked paprika, sea salt, and black pepper, tossing until evenly coated.
Spread the cauliflower and chickpeas in a single layer on the prepared baking sheet.
Roast for 25 to 30 minutes, tossing halfway through, until the cauliflower is tender and the chickpeas are slightly crispy.
While roasting, whisk together the tahini and lemon juice in a small bowl, adding a teaspoon of warm water at a time until a pourable consistency is reached.
Place the fresh arugula in a large serving bowl as your base.
Top the greens with the warm roasted cauliflower and chickpeas.
Generously sprinkle the hemp hearts and nutritional yeast over the top to maximize the protein content.
Drizzle the lemon-tahini dressing over the entire bowl and enjoy immediately.