Preheat your oven to 425°F (220°C).Wash and cut the sweet potatoes into bite-sized cubes. In a bowl, toss them with half the harissa paste, half the garlic powder, half the salt, and a drizzle of EVOO. Spread them on a baking sheet lined with parchment paper. Place the sweet potatoes in the oven and roast for 25-30 minutes, flipping halfway through, until they're tender and slightly crispy.
While the sweet potatoes are roasting, drain and rinse the chickpeas. In a separate bowl, combine the chickpeas and broccoli florets with the remaining harissa paste, garlic powder, salt, and a drizzle of EVOO. Spread them on another baking sheet. Add the chickpeas and broccoli to the oven during the last 15 minutes of the sweet potatoes' roasting time. Roast until the broccoli is tender and the chickpeas are slightly crispy
In a bowl, combine Greek yogurt, finely chopped cucumber, lemon juice, dill, salt, and garlic powder. Mix well and refrigerate until ready to serve
In each serving bowl, add a generous spoonful of tzatziki sauce. Top with roasted sweet potatoes, chickpeas, and broccoli. Garnish with fresh dill or parsley if desired.