Preheat oven to 425° Fahrenheit. Line a cookie sheet with parchment paper and set aside.
In a large bowl, combine the flour, baking powder, kosher salt, and black pepper. Add the butter and with your fingers work the butter into the flour until the mixture resembles coarse sand and you are left with some pea-sized butter pieces. Make a well in the center of the flour mixture.
Combine the ricotta cheese and egg quickly and add to the flour mixture, followed by the parmesan and gruyere cheeses. With a spatula, stir the mixture until just combined. Turn the dough onto a floured surface and pat the dough to a rough rectangle and is at least 1 1/4 inch thick. Fold the dough in half onto itself and pat once more into a rough ¾ inch rectangle, making sure to lightly sprinkle more flour to prevent sticking. Wrap the dough in plastic wrap and place in the refrigerator to chill for about 30 minutes.
Remove the dough from fridge and turn the dough onto a lightly floured work surface. With a round cutter, cut the biscuits and transfer them onto your prepared baking sheet, spacing biscuits about 1 inch apart.. Press the scraps together and pat to 1 1/4 inch thickness. Cut with a round cutter and transfer to prepared baking sheet. Repeat pressing and cutting remaining scraps if needed. Brush tops of biscuits with heavy cream and sprinkle with kosher salt, if desired.
Place in the oven and bake for 15-18 minutes or until the biscuits are golden brown. Serve warm. Makes about 8/10 thick biscuits, or 12-15 thin biscuits (like the ones pictured)
Slightly adapted from Two of a Kind