01 - Preheat oven to 425°F. Line a baking sheet with parchment paper and set aside.
02 - In a large bowl, toss cauliflower florets with 2 tablespoons olive oil, dried oregano, garlic powder, ground cumin, salt, and freshly ground black pepper until evenly coated.
03 - Spread seasoned cauliflower in a single layer on the prepared baking sheet. Roast for 20 to 25 minutes, flipping halfway through, until golden brown and fork-tender.
04 - While the cauliflower roasts, halve the cherry tomatoes, dice the cucumber, thinly slice the red onion, and slice the Kalamata olives.
05 - In a separate bowl, toss the baby spinach leaves with 1 tablespoon olive oil and a pinch of salt until lightly coated.
06 - Divide dressed spinach among four serving bowls as the base. Arrange roasted cauliflower, cherry tomatoes, cucumber, red onion, and olives over the greens.
07 - Top each bowl with crumbled feta cheese, a drizzle of tzatziki sauce, and freshly chopped dill. Serve with lemon wedges on the side.