Cook couscous according to package directions and keep warm. If making in advance, refrigerate until you're ready to use it (no more than 2 days) and bring to room temp or warm in microwave.
Meanwhile, heat oil in large skillet until fairly hot.
Add tomatoes and sprinkle with salt and pepper
Saute tomatoes until they burst and get golden on the underside
Add the spinach and arugula (or your favorite greens) by the handful along with the garlic and more salt and pepper.
Working quickly, saute the vegetables together until the greens wilt to your satisfaction. The whole process should take about 1-2 minutes - TOPS.
Place couscous in a shallow bowl and spoon over tomatoes and greens. Top with cheeses if using and add chicken or a protein if you want. Finish with a healthy drizzle of balsamic and season to taste.