1
Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.
Place 2 TBSP butter (4 TBSP for 4 servings) in a small microwave-safe bowl; bring to room temperature.
Dice potatoes into ½-inch pieces. Peel garlic. Trim, peel, and halve carrots lengthwise; slice into green-bean-size pieces. Trim and thinly slice scallions, separating whites from greens.