Bring a large pot of water to a boil (about 6-8 quarts). Add salt as desired and kale and cook until kale is soft, deep green, and tender, 5 minutes. Fill a large bowl with water and ice. Submerge cooked kale in an ice bath until cooled. Repeat with scallions, cooking for 1 to 2 minutes and shocking in ice water.
Drain the water and fill the pot again for pasta. Bring to a boil. Add salt as desired and add calamarata, cooking until toothsome, 10 to 12 minutes. Reserve 1c. pasta water.
To a blender, add blanched kale, scallions, garlic, and pecorino Romano. With the blender running, add water and olive oil until a creamy, smooth green paste forms. Check for salt and season as desired.
Add sauce to pot of drained and cooled pasta, adding a little pasta water to thin out as needed. Serve with more pecorino romano and fresh lemon zest.