Preheat oven to 425°. Place potatoes and Brussels sprouts in a greased 15x10x1-in. baking pan. Drizzle with 2 tablespoons oil; sprinkle with 1/2 teaspoon salt and pepper. Toss to coat. Roast 20-25 minutes or until tender, stirring once., In a small bowl, whisk lemon juice, garlic, mustard, honey and remaining oil and salt until blended. Transfer vegetables to a large bowl; drizzle with vinaigrette and toss to coat. Serve warm.