In a medium mixing bowl, combine the part-skim ricotta, egg white, grated parmesan, sea salt, black pepper, and ground nutmeg until the mixture is smooth.
Gently fold in the whole wheat flour one tablespoon at a time until a soft, slightly tacky dough forms, being careful not to overwork it.
Bring a large pot of water to a gentle boil and season generously with salt.
Using two small spoons, carefully drop rounded teaspoons of the ricotta dough into the boiling water.
Cook the gnocchi for 2-3 minutes; once they float to the surface, let them cook for 30 more seconds before removing them with a slotted spoon.
In a large non-stick skillet over medium heat, melt the grass-fed butter and add the fresh sage leaves, cooking until the leaves are crisp and the butter is fragrant.
Add the boiled gnocchi to the skillet and sear for 1-2 minutes per side until they develop a light golden crust.
Add the fresh baby spinach and lemon juice to the skillet, tossing gently for 30 seconds until the spinach is just wilted, then serve immediately.