1
Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.
Cut potatoes into ½-inch-thick wedges. Trim and thinly slice mushrooms (skip if your mushrooms are pre-sliced!). Halve, peel, and thinly slice onion.
In a small bowl, combine mayonnaise with ¼ tsp garlic powder (½ tsp for 4 servings); season with salt and pepper. (You’ll use the rest of the garlic powder in the next step.)
Trim and discard woody bottom ends from asparagus. (Save potatoes for another use.)