1. Preheat oven to 425°. Cut potatoes in half lengthwise; toss with jerk seasoning and 1 Tbsp. oil. Arrange, cut sides down, in a single layer on a lightly greased baking sheet. Bake 15 minutes; turn and bake 8 to 10 minutes or until tender. Cool on a wire rack 20 minutes.
2. Whisk together lime juice, salt, and remaining 3 Tbsp. oil in a large bowl. Add arugula and next 5 ingredients, and toss to coat. Arrange on a platter; top with potatoes.