Preheat oven to 350°F (175°C).

Spread pecans on a baking sheet.

Toast pecans for 5-10 minutes, until fragrant and lightly golden.

Let the toasted pecans cool completely.

In a food processor, combine spinach, cooled pecans, Parmesan cheese, minced garlic, salt, pepper, lemon juice, and lemon zest.

Add 2 tablespoons of olive oil to the food processor.

Pulse the food processor a few times to combine the ingredients.

With the food processor running, slowly drizzle in the remaining olive oil until the pesto is well combined and smooth.

Use the spinach pesto immediately.

For freezing, portion the pesto into an ice cube tray.

Freeze the pesto cubes until solid.

Once frozen, transfer the pesto cubes to a ziplock bag.

Store the frozen pesto cubes in the freezer for up to 3 months.

Thaw the frozen pesto before using in your favorite recipes.