Place the ricotta cheese in a fine-mesh strainer or paper towel to drain any excess liquid for 10 minutes.
Cut the chicken breast into bite-sized pieces and season with half of the sea salt and black pepper.
In a medium bowl, combine the drained ricotta, egg yolk, all-purpose flour, and the remaining salt and pepper until a soft dough forms.
On a lightly floured surface, roll the dough into a long rope and cut into 1-inch gnocchi pieces.
Heat a non-stick skillet over medium-high heat and sear the chicken until golden brown and cooked through, then remove from the pan.
Bring a small pot of salted water to a boil and cook the gnocchi until they float to the surface, about 2-3 minutes, then drain.
In the same skillet used for the chicken, melt the butter over medium heat until it begins to foam.
Add the garlic and sage leaves to the butter, frying for 1 minute until the sage is crisp and the butter is slightly browned.
Return the chicken and gnocchi to the skillet, tossing gently to coat everything in the sage butter before serving.