1. Preheat oven to 350°.
2. Place bread in a food processor; pulse 10 times or until coarse crumbs measure 1/2 cup. Spread crumbs on a baking sheet. Bake at 350° for 5 minutes or until golden.
3. Increase oven temperature to 450°.
4. Combine 4 teaspoons oil, mustard, salt, pepper, and rind in a large bowl; stir well with a whisk.
5. Combine potatoes, onion, and remaining 1 1/2 teaspoons oil in a large bowl; toss well to coat. Place potato mixture on a foil-lined jelly-roll pan coated with cooking spray. Bake at 450° for 20 minutes. Add tomatoes and olives to pan. Bake an additional 10 minutes or until potatoes are tender. Add potato mixture to mustard mixture; toss gently to coat. Sprinkle with breadcrumbs.