Cook the kale. Bring a large pot of water to a boil. Add 1 tsp Kosher salt, then add ripped kale leaves. Cook for 5 minutes, then use tongs or a slotted spoon to transfer cooked kale to a blender or food processor. Reserve cooking water.
Make the kale sauce. To the blender add ½ cup reserved cooking water, ¼ cup walnuts, 2 Tbsp extra virgin olive oil, 1 tsp Kosher salt, and ¼ tsp black pepper. Blend or process until very smooth. If needed, add additional olive oil, 1-2 tablespoons at a time, to help loosen the sauce. Set aside.
Crisp the pancetta. Heat a skillet over medium-high heat. Add cubed pancetta then cook for 3-5 minutes (cook time depends on the size of the pancetta cubes, see note), until golden brown and lightly crispy. Drain on a paper towel.
Cook the gnocchi. Return the pot of water the kale cooked in to a rapid boil. Add the gnocchi and cook according to package directions. Reserve ½ cup of cooking liquid, then drain gnocchi.
Assemble kale gnocchi. Heat 1 Tbsp butter and 1 Tbsp olive oil in a large skillet. When melted, add garlic and red pepper flakes. Cook for 30 seconds, until fragrant, then pour drained gnocchi on top. Allow gnocchi to cook for a minute before stirring so they get light golden brown. Pour kale sauce, mascarpone, grated Pecorino, and ¼ cup reserved pasta cooking water on top, then stir to thoroughly combine. If you want more of a sauce, add remaining ¼ cup reserved water. Return crispy pancetta to the pan, then toss one final time. Divide gnocchi into serving bowls.
Finish gnocchi. Garnish gnocchi with additional grated Pecorino cheese, crushed walnuts, and a drizzle of a high quality finishing olive oil and a tiny pinch of flaky sea salt, if using.