Bring a large pot of well-salted water to a boil. Add pasta and cook until al dente.
Remove 1 cup of pasta cooking water (set aside), then drain pasta in a colander.
While pasta cooks, pulse walnuts and garlic clove in a food processor until finely chopped.
Add kale, olive oil, Parmesan, 2 tablespoons lemon juice, and salt. Process until smooth, scraping down the sides as needed.
Taste, then season with additional lemon juice and salt, if desired. Set aside.
When pasta is finished cooking, return to pot (off heat). Add pesto.
Mix pasta and pesto together using a pair of tongs or two wood spoons. Add just enough of the pasta cooking water to help the pesto evenly coat the pasta.
When pasta and pesto are mostly combined, add tomatoes and feta. Toss to combine.
Serve pasta hot. Enjoy!
Any variety of kale will work for the pesto.I prefer to make this recipe with spaghetti, but you can substitute your favorite kind of pasta. Shapes such as fusilli or cavatappi are great for capturing the sauce.This pasta recipe is super simple as-is, but feel free to get creative depending on what's in your refrigerator. Try adding other ingredients, such as sauteed kale, mushrooms, or roasted vegetables. Other cheeses, such as goat cheese, would also be delicious. (See more tips before the recipe.)Make this recipe vegan by skipping the cheese. You could also replace the Parmesan in the pesto with a nutritional yeast (to taste).