Adjust rack to top position and preheat oven to 425 degrees. Wash and dry all produce. Mince garlic. In a medium bowl, combine yogurt, half the garlic, half the Shawarma Spice (you’ll use the rest later), 1 TBSP olive oil, 1 tsp salt, and pepper. (For 4 servings, use 2 TBSP olive oil and 2 tsp salt.) Pat chicken dry with paper towels; add to bowl and turn to coat. Set aside to marinate.

Trim and dice zucchini into 1/2-inch pieces. Dice tomato into 1-inch pieces. Trim and thinly slice scallions, separating whites from greens. Quarter lemon. In a small bowl, combine sour cream and remaining garlic to taste. Season with salt and pepper. Stir in water 1 tsp at a time until mixture reaches a drizzling consistency.

Toss zucchini and tomato on a baking sheet with a drizzle of olive oil, remaining Shawarma Spice, salt, and pepper. Roast on top rack until veggies are browned and tender, 15-18 minutes.

Meanwhile, heat a drizzle of olive oil in a large, preferably nonstick, pan over medium heat. Remove chicken from marinade; allow excess to drip off. Add chicken and cook until browned and cooked through, 6-8 minutes per side. (TIP: Medium heat is key in preventing the marinade from burning. If chicken begins to brown too quickly, lower the heat.) Turn off heat; transfer chicken to a cutting board. Once cool enough to handle, slice crosswise.

While chicken cooks, heat a drizzle of olive oil in a small pot over mediumhigh heat. Add scallion whites; cook until slightly softened, 1 minute. Add stock concentrate, 3/4 cup water, 1/4 tsp turmeric (be sure to measure), 1 TBSP butter, and a pinch of salt. (For 4 servings, use 11/2 cups water, 1/2 tsp turmeric, and 2 TBSP butter.) Once boiling, stir in couscous; cover pot and remove from heat. Let stand until water has absorbed and couscous is tender, at least 5 minutes.

Fluff couscous with a fork and season with salt and pepper. Toss roasted veggies with a big squeeze of lemon juice. Divide couscous and veggies between bowls; top with chicken and dollop with hummus. Drizzle with white sauce and hot sauce to taste. Sprinkle with scallion greens. Serve with remaining lemon wedges on the side.