Mexican Crema - cooking recipe

Ingredients

1 cup whipping cream (preferably not ultra-pasteurized)
2 tablespoons buttermilk

Preparation

In a small glass bowl, combine both ingredients.
Cover the bowl loosely, and let it stand at room temperature for 8 to 24 hours, until the cream is thickened and tart.
Stir it well, cover it tightly and refrigerate it.
Use it as needed.
Crema keeps for up to 10 days.