Place the ricotta cheese in a fine-mesh sieve over a bowl and let it drain for 10 minutes to remove excess moisture.
In a medium mixing bowl, whisk together the drained ricotta, liquid egg whites, grated parmesan, sea salt, black pepper, and ground nutmeg until the mixture is completely smooth.
Gently fold in the cassava flour one tablespoon at a time until a soft, slightly tacky dough forms, being careful not to overwork the mixture.
Lightly dust a clean work surface with a pinch of cassava flour and roll the dough into long ropes about half an inch thick.
Cut the ropes into 1-inch pieces and use the back of a fork to create small ridges on each gnocchi piece.
Bring a large pot of salted water to a gentle boil and drop the gnocchi in, cooking until they float to the surface, which should take about 2 to 3 minutes.
While the gnocchi are boiling, melt the ghee in a large non-stick skillet over medium heat and add the fresh sage leaves, cooking until they are crisp and the ghee is fragrant.
Use a slotted spoon to transfer the cooked gnocchi directly from the water into the skillet with the sage butter.
Sauté the gnocchi for 2 minutes, tossing gently until they are lightly golden and well-coated before serving immediately.