While The New York Times didn’t call this dish yogurt, I found that it basically is. My version uses less cream, and I’d encourage you to use whatever sliced seasonal fruit or roasted nuts you have on hand. Also, I don’t know why, but I really love this when it has a chance to come to room temperature just a bit rather than right out of the refrigerator. Do note that it must chill overnight in the refrigerator, and that time isn’t accounted for in the total time above.
Put a colander inside a large bowl; wet a clean kitchen towel and wring out as much water as you can. Fold it in half to create a double layer; line the colander with it. Add the buttermilk and cover with plastic wrap; refrigerate for 24 hours.
In the morning, remove the buttermilk from the refrigerator and use a spatula to scrape the thickened buttermilk from the towel into a bowl and stir it until it’s smooth and creamy. Discard the liquid that has strained away into the bowl (or use a little to drizzle on top along with the honey).
In a separate bowl, use electric beaters to beat the cream to a soft peak. Fold the cream into the buttermilk. Portion into individual bowls and top with diced mango and ground pistachio. Drizzle a healthy spoonful of honey on each.