Place the heavy cream in a container that can be sealed airtight. Add the buttermilk and mix well. Seal the container shut and leave it at room temperature for 1-2 days or until it thickens.
Refrigerate when ready. Use as a topper for enchiladas, tacos, or soups. Note: this crema will last for about 1 week.
Recipe reprinted with permission © 2021 Iliana de la Vega