- Cook the spaghetti according to package directions.
- Drain the spaghetti, reserving approximately ½ cup of the pasta water.
- Set spaghetti and ½ cup pasta water aside.
- In a food processor, add the basil, spinach, pecans, lemon zest, garlic cloves, salt, black pepper, and Parmesan cheese. Pulse 15 to 20 times until the ingredients are coarsely chopped.
- With the food processor set on low speed, slowly pour the olive oil through the food chute until all ingredients are incorporated.
- In a large skillet over very low heat, add the pesto, ¼ cup of the reserved pasta water and stir to combine.
- Add the spaghetti and toss to coat, add more pasta water as needed until desired consistency is achieved and the spaghetti is heated through.
- Add salt and pepper, to taste.
- Add a dash red pepper for a little zing, if desired.
- Garnish with pecans and serve.
NOTE: The pesto can be stored in an airtight container in the refrigerator for up to two weeks.