Course salt and freshly ground black pepper to taste
Place stock in a large saucepan over high heat. Bring to a boil and remove immediately from heat. Season with salt and pepper. Add couscous, stir and cover. Let stand 5 minutes or until liquid is absorbed.
Meanwhile, heat oil in a large sauté pan over medium high heat. When hot, add tomatoes, spinach leaves, walnuts, garlic and shallot. Sauté for 3 minutes or until tomatoes start to soften. Add basil and toss well. Season with salt and pepper.
Fluff couscous with a fork and transfer to serving bowl. Add tomato mixture and gently combine.