Heat the oven to 450 degrees and arrange racks on the top and bottom thirds of the oven. Line two sheet pans with foil or parchment paper for easy cleanup. Combine the cumin, coriander, turmeric, cayenne and ½ teaspoon salt in a small bowl and stir to combine. Set aside.

Combine all ingredients in a jar with a tight-fitting lid and shake well. Set aside.

While the oven is preheating, prepare the couscous. Bring broth to a boil then add couscous and reduce heat to maintain a steady simmer for 8 minutes. Drain couscous well, drizzle lightly with olive oil and stir to coat. Set aside.

Combine drained chickpeas with 2 tablespoons of olive oil on one of the prepared sheet pans. Shake the pan gently to coat the chickpeas with oil. Sprinkle with the prepared spice mixture and shake the pan again to combine.

On the second sheet pan, combine bell peppers, onion and jalapeños with the 2 tablespoons of oil. Sprinkle lightly with kosher salt and freshly ground black pepper. Spread the vegetables into one layer.

Place the chickpea pan on the bottom rack and vegetables on the top rack and roast for 5 minutes. Remove veggie pan from the oven and add the halved tomatoes. Drizzle the tomatoes lightly with a bit more olive oil and return pan to the oven. After a total of 12 minutes, remove both pans from the oven.

Arrange couscous on a large platter. Top with the veggies, then the chickpeas. Drizzle with half of the dressing. Top with fresh herbs and pine nuts. Pass extra dressing in a small bowl at the table, if desired.