Wash and dry all produce. Trim, then thinly slice scallions, separating whites from greens. Zest and quarter lemon.

Pat chicken dry with a paper towel; season all over with salt, pepper, and half the Mediterranean Spice (use the rest as you like). Heat a large drizzle of olive oil in a large pan over medium-high heat. Add chicken and cook until browned and cooked through, 3-5 minutes per side. Turn off heat; transfer chicken to a plate.

While chicken cooks, combine couscous, stock concentrate, 3/4 cup water, 1/2 TBSP butter, and a pinch of salt in a large microwave-safe bowl. Cover bowl with plastic wrap, then microwave on high until liquid is boiling, about 1 minute. Set aside, covered, until ready to serve.

In a small bowl, combine sour cream, lemon zest, 1 TBSP water, 1/4 tsp harissa, and a pinch of salt. Taste and add more harissa if you like.

Heat another drizzle of olive oil over medium-high heat in pan used to cook chicken. Add scallion whites and carrots. Cook, stirring, until softened, 1-2 minutes. Turn off heat. Squeeze in juice from 1 lemon wedge. Season with salt.

Fluff couscous with a fork. Stir in carrot mixture. Divide finished couscous between bowls. Top with chicken. Drizzle with crema. Garnish with scallion greens. Serve with remaining lemon wedges on the side for squeezing over.