Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Cut the tempeh into 1/2-inch cubes and thoroughly rinse and pat the chickpeas dry with a clean kitchen towel.
Chop the cauliflower into small florets and slice the zucchini into bite-sized half-moons.
Place the tempeh, chickpeas, cauliflower, and zucchini onto the prepared baking sheet.
Drizzle the olive oil over the ingredients and sprinkle with garlic powder, smoked paprika, sea salt, and black pepper.
Toss everything together with your hands or a spatula to ensure an even coating of oil and spices, then spread into a single layer.
Roast for 22 to 25 minutes, tossing the mixture halfway through, until the vegetables are tender and the tempeh is golden brown.
Remove from the oven, sprinkle the nutritional yeast over the hot vegetables, and finish with a fresh squeeze of lemon juice before serving.