The first time I ever tasted the combination of feta, yogurt and blue cheese was many moons ago, at the first conference of the Oldways Preservation and Exchange Trust, which was held in Porto Carras, in northern Greece. I am not exactly reinventing the wheel here, just providing an easy, savory dip that you can whip up almost instantly and that happens to be a great dish for entertaining.
Combine cheeses, yogurt, hot sauce, and pepper in a bowl, mixing until smooth. Transfer to a serving bowl and garnish with walnuts, radishes or chives. Alternatively, fill Belgian endive leaves with the mixture and serve on a small platter, garnished.