Mix cumin, coriander, paprika, cinnamon, turmeric, 3/4 tsp salt, and pepper; rub over chicken.
Heat 1 tbsp oil in a skillet over medium-high; sear chicken 3 minutes per side until browned.
Transfer skillet to 375°F oven for 10–12 minutes or until internal temp hits 165°F; rest 5 minutes.
In another pan, heat remaining oil; sauté onion until soft, add garlic 30 seconds, then stir in couscous and toasted 1 minute.
Pour in broth, add raisins, cover and remove from heat; let sit 5 minutes, fluff with fork and stir in lemon and herbs.
Slice chicken and serve over couscous, spooning pan juices over top.