Prep: Bring chicken to room temperature for 10–15 minutes if you can (this helps even cooking). Rinse couscous briefly if desired and drain. Preheat a skillet over medium-high heat.
Cook the couscous: In a small saucepan bring 1 1/4 cups chicken broth (or water) to a boil. Add the couscous, stir, reduce heat to low, cover, and simmer until tender according to package directions (usually 8–10 minutes). Fluff with a fork and set aside to cool slightly. (Tip: for nuttier flavor, toast couscous in the dry pan 2–3 minutes before adding broth.)
Season the chicken: Pat the chicken breasts dry. Rub them with 1 tbsp olive oil, smoked paprika, dried oregano, and a generous pinch of salt and pepper.
Sear the chicken: Heat 1 tbsp olive oil in the skillet until shimmering. Add the chicken and sear 4–5 minutes per side (time depends on thickness) until a golden crust forms and the internal temperature reaches 165°F (74°C). Remove to a cutting board and let rest 5–7 minutes, then slice thinly against the grain.
Make the dressing: Whisk together 3 tbsp olive oil, 2 tbsp red wine vinegar, 1 tsp Dijon, minced garlic, and a pinch of salt and pepper. Taste and adjust acid or salt as needed.
Combine salad components: In a large bowl, toss warm (or room-temperature) couscous with cherry tomatoes, cucumber, Kalamata olives, red onion, parsley, and crumbled feta. Pour about two-thirds of the dressing over the mixture and toss gently to coat.
Finish & serve: Arrange the sliced chicken over the dressed couscous salad (or toss the chicken in if you prefer it distributed). Drizzle remaining dressing over the top, finish with an extra sprinkle of parsley and a crack of black pepper, and serve with lemon wedges if desired.