Heat olive oil in a large skillet over medium heat.

Add chopped onions and minced garlic to the skillet and sauté until they start to brown.

Add diced tomatoes, white wine (or chicken stock), lemon juice, and lemon zest to the skillet.

Reduce the mixture until it's almost dry.

Add chicken stock and simmer over medium-low heat for 10 minutes to reduce the sauce slightly.

Prepare couscous separately and keep warm until ready to serve.

Stir shrimp into the sauce and simmer until the shrimp are cooked through.

If the sauce is too thin, thicken it with cornstarch to achieve the desired consistency.

Remove the skillet from the heat and stir in capers, olives, and minced herbs.

Divide couscous onto 4 serving plates.

Spoon the shrimp and sauce over the couscous.

Sprinkle with crumbled feta cheese.

Serve immediately.