Adjust racks to middle and top positions and preheat oven to 425 degrees. Wash and dry all produce. Trim zucchini, then dice into 1/2-inch pieces. Halve tomatoes. Strip thyme leaves from stems; discard stems. Mince garlic. Trim and thinly slice scallions, separating whites from greens. Halve lemon.

Toss zucchini, tomatoes, and half the thyme on a baking sheet with a large drizzle of olive oil. Season with salt and pepper. Roast on middle rack, tossing halfway through, until tender, 15-20 minutes.

Meanwhile, drain and rinse chickpeas. Pat as dry as possible with paper towels. On a second baking sheet, toss half the chickpeas (all the chickpeas for 4 servings) with paprika, a large drizzle of olive oil, and a pinch of salt and pepper. Roast on top rack, tossing halfway through, until crisp, 18-20 minutes. TIP: It’s natural for the chickpeas to pop a bit.

Heat 1 TBSP butter (2 TBSP for 4 servings), garlic, and scallion whites in a medium pot over medium-high heat. Once butter is melted and garlic is fragrant, add couscous and remaining thyme; stir to coat. Season with salt and pepper. Cook, stirring, until couscous is lightly toasted, 2-3 minutes.

Add stock concentrate and 3/4 cup water (11/2 cups for 4 servings) into pot with couscous. Bring to a boil, then cover and reduce heat to low. Cook until couscous is tender, 6-8 minutes. Drain any excess water, if necessary. Keep covered until ready to serve.

Add half the veggies, half the feta, and a squeeze of lemon juice to pot with couscous; stir to combine. Season with salt and pepper. Divide between plates; top with roasted chickpeas, remaining veggies, scallion greens, and remaining feta.