Heat oil in a large skillet over medium heat. Cook garlic and pepper flakes until tender, about 1 minute. Add greens and cook, stirring until tender, about 5 minutes. Remove from heat and stir in pine nuts and lemon zest and juice. Season with salt.
Meanwhile, cook pasta in well-salted water according to package directions. Reserve 1/2 cup pasta water and then drain.
Add pasta to skillet, tossing to coat, and add reserved water to adjust consistency. Sprinkle with lemon zest and cheese before serving.
These noodles are made from farro, an Italian whole grain that's gained a following for its complex, nutty flavor and high protein content.