Preheat the oven to 350 degrees . On a baking sheet, toss the bread with the olive oil; season with salt. Bake, tossing occasionally, until lightly golden, about 30 minutes. Let cool, then transfer to a large bowl.
Meanwhile, in a small saucepan, bring the chicken broth to a boil and cook until reduced by half, about 5 minutes. Remove from the heat and stir in 3 tablespoons nicoise salad dressing. Drizzle the mixture over the croutons, tossing to coat.
In a serving bowl, toss the lettuce with the remaining salad dressing just before serving; top with the croutons.