This dish is one of our sexy vanilla recipes.
In a medium bowl, combine balsamic vinegar with a pinch of salt. Slowly whisk in 1/3 cup of vanilla-infused olive oil. Place shrimp in another bowl, and pour half of balsamic dressing on top. Refrigerate shrimp for 30 minutes.
Split remaining 1/2 bean lengthwise, and scrape out seeds. Transfer seeds and pod to a small saucepan with chicken broth and saffron. Bring to a boil, then reduce to a simmer and cook about 3 minutes. Add basil, butter, couscous, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Bring mixture back to a boil, then reduce to a simmer; cover and cook until couscous is tender and most of broth is absorbed, 8 to 10 minutes.
Meanwhile, heat 2 tablespoons vanilla olive oil in a large sauté pan over medium-high heat. Add shrimp and 1/2 teaspoon salt. Sauté on one side for 3 minutes, then sauté other side until crisp and opaque, 3 minutes more.
Place couscous on 2 plates; garnish with basil leaves (if using). Arrange shrimp on top, add pepper to taste, and drizzle with remaining vanilla-balsamic vinaigrette. Serve immediately.