You can find recipes that specify anything and everything nowadays - whether the items exist or not. We are constantly surprised by the number of cookbook writers who specify ingredients that are almost impossible to obtain or concoct, and even more surprised that there are publishers who let them get away with it.

If your recipe is in a cookbook, it is quite possible that somewhere near the front of the book the author has provided a section on special ingredients and basic recipes that you will need to make full use of the book. It may be that his or her special Coulis Mascarpone-Yogurt À La Grand-Mère is hidden there.

We are not aware of any hybrid mascarpone-yogurt product on the market, although we have come across a number of recipes that blend the two ingredients. The yogurt appears to be used to tone down the richness of the cheese and make people think that they are making a "healthy" dish. Among the recipes we've seen, the ratio of mascarpone to yogurt ranges from a 1-to-1 mix up to 1 part mascarpone to 2 parts yogurt.