1. Bring a large pot of well-salted water to a boil.
2. In a food processor, combine the spinach, basil, pine nuts, garlic, and 1/2 teaspoon fine sea salt. With the machine running, add the oil in a slow and steady stream; pulsing until smooth.
3. Cook the pasta in the boiling water until al dente. Reserving 1/4 cup of the cooking liquid, drain the pasta, then add it back to the pot off the heat.
Immediately add the pesto and chicken, and stir to combine thoroughly. Moisten with 2 tablespoons of the pasta cooking liquid, or more, if desired.
4. Serve immediately, drizzled with a touch of olive oil and topped with the cheese and extra salt to taste.
Recipe adapted from Food Republic:
http://www.foodrepublic.com/2011/06/29/spinach-pesto-pasta-chicken-recipe