Toast rice: Trim ends from scallions, then thinly slice on an angle. Heat 1 tablespoon oil in a small saucepan over medium-high. Add half of the scallions and cook until softened, about 1 minute. Add rice and cook until fragrant and toasted, 2–3 minutes.

Cook rice pilaf: Add 1¼ cups water and ½ teaspoon salt to saucepan, stir, and bring to a boil. Cover, reduce heat to simmer, and cook until water is absorbed and rice is tender, about 17 minutes. Cover to keep warm until ready to serve.

Prep ingredients: While rice pilaf cooks, peel and finely grate 2 large garlic cloves. Grate ½ teaspoon lemon zest, then squeeze 1 tablespoon lemon juice into a separate small bowl. Cut any remaining lemon into wedges. Cut tomato into ¼-inch pieces.

Make tomato salsa: In a medium bowl, combine tomatoes, lemon zest, ¼ teaspoon of grated garlic, and 1½ tablespoons oil. Season to taste with salt and pepper.

Season & broil shrimp: Preheat broiler with top rack 6 inches from heat source. In a large bowl, toss shrimp with lemon juice, remaining garlic, 2 teaspoons za'atar, 1½ tablespoons oil, ¼ teaspoon salt, and a few grinds pepper. Transfer to a rimmed baking sheet. Broil shrimp on top oven rack until almost cooked through, 1–2 minutes (watch closely as broilers vary).

Broil shrimp & serve: Sprinkle spinach over shrimp on baking sheet. Broil, about 30 seconds. Remove from oven, and toss to wilt spinach. Fluff rice pilaf with a fork. Serve rice pilaf topped with shrimp, tomato salsa, remaining scallions, and any lemon wedges on the side for squeezing. Drizzle with olive oil and garnish with a few grinds pepper.