Preheat the oven to 425°F (220°C) and line a large rimmed baking sheet with parchment paper if desired.
Place the cauliflower florets on the baking sheet and toss with 3 tablespoons olive oil, 1 teaspoon dried oregano, 1 teaspoon smoked paprika, ½ teaspoon kosher salt, and ¼ teaspoon black pepper. Spread into a single layer.
Roast the cauliflower for 25–30 minutes, turning the florets halfway through, until tender and browned around the edges.
Meanwhile, bring a large pot of salted water to a boil. Cook the 10 ounces orzo according to the package directions until al dente, then drain thoroughly.
Transfer the warm orzo to a large mixing bowl. Add the remaining 1 tablespoon olive oil, minced garlic, 1 teaspoon lemon zest, remaining 1 teaspoon oregano, and remaining ½ teaspoon salt, then toss gently.
Add the drained chickpeas and fold them into the orzo.
Add the roasted cauliflower, chopped parsley, optional dill, and crumbled feta, then gently toss until evenly distributed.
Add about 2 tablespoons fresh lemon juice, toss, and taste. Add more lemon juice if desired, adjusting the seasoning with additional black pepper or salt only if needed.
Let the orzo rest for about 5 minutes, then serve warm or at room temperature with additional parsley and lemon wedges if desired.