Toast the walnuts in a nonstick skillet over medium low heat, shaking or stirring to make sure they don’t burn. Pulse the walnuts, parmesan, olive oil, garlic, lemon juice, salt, and pepper until a textured paste forms. Set aside.
Bring a pot of water to boil. Add the gnocchi and cook until they float to the top of the water. Drain and set aside.
While the gnocchi is cooking, heat the butter in a large skillet over medium high heat. Add the mushrooms and saute for a few minutes until the mushrooms are browned. Remove from heat and set aside.
Add the gnocchi to the mushrooms in the pan. Over medium high heat, stir in about half of the walnut mixture. Things will get a little sticky because of the Parmesan, but if you keep browning it, you will end up with gnocchi pieces that have that perfectly golden brown textured exterior (and mushrooms, too). Add the herbs and toss gently to combine.
