This colorful salad—adapted from a recipe in Pierre Thiam’s cookbook, “Yolele!”—is a refreshing combination of sweet, sour, spicy and herbal flavors. Rof is a Senegalese mixture of parsley, scallions, chilies and garlic. It’s typically used as a stuffing or garnish but here we make it into a pesto-like dressing. It’s worth seeking out roasted peanut oil for this salad, as it adds deep, nutty notes and a rich aroma, but regular peanut oil or extra-virgin olive oil worked, too. If you have flaky sea salt, use it instead of kosher salt for sprinkling on the mangoes and avocados; the crunch adds dimension to the dish.