Heat 1 tablespoon olive oil in a medium saucepan over medium heat. Add the Israeli couscous and toast, stirring frequently, until golden and nutty-smelling, about 3-4 minutes. Pour in the chicken broth and 1/2 teaspoon salt, bring to a boil, then reduce heat to low, cover, and simmer until tender and liquid is absorbed, 10-12 minutes. Fluff with a fork and set aside.

While the couscous cooks, pat the shrimp completely dry with paper towels - this is crucial for browning. Heat 1 tablespoon olive oil in a large skillet over medium-high heat until shimmering. Add half the shrimp in a single layer, season lightly with salt, and cook undisturbed until pink and just opaque, about 2 minutes per side. Transfer to a plate and repeat with remaining 1 tablespoon oil and shrimp.

Reduce heat to medium. Add the minced garlic to the same skillet and cook until fragrant, about 30 seconds, scraping up any browned bits. Add the cherry tomatoes and cook until they start to soften and release their juices, 3-4 minutes. Remove from heat.

Add the cooked couscous, shrimp, diced cucumber, lemon juice, and lemon zest to the skillet with the tomatoes. Toss gently to combine and warm through. Fold in the fresh dill and half the feta. Taste and adjust seasoning with salt and plenty of black pepper. Transfer to a serving dish and top with remaining feta and a drizzle of olive oil. Serve immediately while warm or at room temperature.