1
Adjust rack to top position and preheat oven to 425 degrees. In a medium pot, bring 5 cups water to a boil (use a large pot and 8 cups water for 4 servings), then reduce to a low simmer. (You’ll use the water in Step 4.) Wash and dry produce.
Trim and thinly slice mushrooms (skip if your mushrooms are pre-sliced!). Trim and thinly slice scallions, separating whites from greens. Peel and mince or grate garlic.