Bring a large pot of salted water to a boil. Meanwhile, in a food processor, combine tomatoes, garlic, tomato paste, walnuts, basil, pepper flakes and Pecorino; pulse to combine. With motor running, add olive oil in a steady stream until a thick sauce forms.
Add capellini to boiling water and cook until al dente according to package instructions. Divide pasta among bowls and top with pesto. Sprinkle with additional Pecorino and a drizzle of olive oil, if desired.
Before her diagnosis, Caroline wrote a book on cakes called Cake Magic!. She started developing a birthday cake using her gluten-free mix found in that book. Check out other recipes she’s developing for her new life—and the stories behind them—on her blog, The Wright Recipes. Her next book, Catalan Food, written with chef Daniel Olivella, comes out in early September from Clarkson Potter.