Heat broiler to high. Wash and dry produce.

Halve, peel, and cut onion into 1-inch-thick wedges; mince one wedge. Trim and halve zucchini lengthwise; thinly slice lengthwise into long wedges. Halve tomatoes. Zest and quarter lemon. Roughly chop cilantro.

Heat a drizzle of oil in a small pot over medium-high heat. Add minced onion and couscous. Cook, stirring, until onion is softened and couscous is lightly toasted, 2-3 minutes.

Add 1 cup water (2 cups for 4 servings) and stock concentrate. Bring to a boil, then cover and reduce to a low simmer. Cook until couscous is tender, 6-8 minutes.

Keep covered off heat until ready to use in step 5.

Meanwhile, toss zucchini and onion wedges on a baking sheet with a large drizzle of oil, sumac, salt, and pepper.

Broil, tossing halfway through, until lightly charred, 10-15 minutes. TIP: Watch carefully to avoid burning.

While veggies cook, slice grilling cheese into four large pieces (eight pieces for 4 servings).

Place Za’atar Spice on a plate. Coat cheese in spice, pressing to adhere.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add cheese and cook until browned, 1-2 minutes per side.

Transfer cooked couscous to a large bowl. Stir in tomatoes, lemon zest, half the broiled veggies, half the cilantro, and a squeeze of lemon juice. Season with salt and pepper.

Divide couscous mixture between plates. Top with remaining broiled veggies and grilling cheese. Garnish with remaining cilantro. Serve with remaining lemon wedges on the side.