Preheat oven to 425°F. Toss zucchini rounds on a parchment-lined baking sheet with olive oil, half the Tuscan spice, salt, and pepper. Arrange in single layer.

Mix panko breadcrumbs and cheese with a drizzle of olive oil. Top each zucchini round with about 1 teaspoon of mixture, pressing gently. Roast for 15-18 minutes until tender and topping is golden and crispy.

Heat 1 tablespoon olive oil in small pot over medium-high heat. Sauté scallion whites for 1 minute. Add couscous and stir for 30 seconds to toast. Add 1 cup water and half the chicken stock. Bring to boil, cover, reduce to low, and simmer 6-8 minutes until tender.

Pat chicken dry and season both sides with remaining Tuscan spice, salt, and pepper. Heat 1 tablespoon olive oil in large skillet over medium-high heat. Cook chicken 3-5 minutes per side until golden and cooked through (165°F). Transfer to plate.

Add remaining chicken stock and squeeze of lemon juice to the same pan. Scrape up browned bits and simmer 2-3 minutes to reduce. Turn off heat and whisk in sour cream and 1 tablespoon butter until smooth.

Fluff couscous and stir in lemon zest, squeeze of lemon juice, scallion greens, and remaining 1 tablespoon butter. Plate chicken with sauce, crispy zucchini, and herbed couscous.