1
Adjust rack to top position and preheat oven to 425 degrees. Place garlic herb butter in a large bowl; bring to room temperature (you’ll use it in step 4). Wash and dry produce.
Trim and thinly slice scallions, separating whites from greens. Place peppercorns in a zip-close bag; crush with a rolling pin or a heavy-bottomed pan. Halve baguette lengthwise. Zest and quarter lemon (for 4 servings, zest one lemon and quarter both).