Pour water into a pot and bring to a boil over medium-high heat. Stir in couscous, cover, reduce heat to low, and simmer until couscous is cooked and water is fully absorbed, 8 to 10 minutes. Transfer couscous to a large bowl and set aside.
Meanwhile, heat olive oil in a saucepan over medium heat. Add onion and cook until slightly caramelized, 8 to 10 minutes. Stir in garlic and cook until fragrant, about 1 minute. Add dried figs and cook until slightly softened, about 5 minutes. Mix in balsamic vinegar, honey, salt, and black pepper, and cook until mixture thickens slightly, 4 to 5 minutes. Pour fig mixture over cooked couscous and stir to combine. Adjust salt and pepper to taste. Add 2 tablespoons of crumbled Gorgonzola and the toasted walnuts to the couscous; toss to combine.
Divide spinach between four serving dishes. Top each with equal amounts of fig and couscous mixture. Top each salad with additional Gorgonzola crumbles, if desired. Serve immediately.
