In a medium bowl, combine the part-skim ricotta, egg whites, grated parmesan, sea salt, and black pepper until smooth.
Gently fold in the all-purpose flour until a soft, slightly tacky dough forms; avoid over-mixing to keep the gnocchi light.
Bring a medium pot of salted water to a gentle boil.
Using two small spoons, drop small, uniform dollops of the ricotta mixture into the boiling water.
Cook the gnocchi for 2-3 minutes or until they float to the surface, then remove with a slotted spoon and set aside.
In a large non-stick skillet, melt the unsalted butter over medium heat until it begins to foam.
Add the fresh sage leaves and minced garlic to the skillet, sautéing for 1 minute until the sage is crisp and the butter smells nutty.
Stir in the shredded cooked chicken breast and fresh spinach, cooking until the spinach is just wilted.
Add the cooked gnocchi to the skillet and toss gently for 1-2 minutes to coat them in the aromatic sage butter.
Serve immediately while warm.