Wash the spinach thoroughly and pat dry with paper towels or use a salad spinner. Remove any thick stems. If using frozen spinach, thaw completely and squeeze out all excess moisture—this is crucial for the right consistency.

Place pine nuts in a dry skillet over medium heat for 2-3 minutes, stirring constantly until fragrant and lightly golden. This deepens the flavor significantly. Let cool for 5 minutes.

Add spinach, basil (if using), toasted nuts, and garlic to your food processor. Pulse 10-15 times until roughly chopped and combined.

With the processor running, slowly drizzle in the olive oil through the feed tube. Scrape down the sides as needed. Continue blending until you reach your desired consistency—I prefer mine slightly chunky for texture.

Add the Parmesan cheese, lemon juice, salt, and pepper. Pulse another 5-10 times until well combined. Taste and adjust seasoning—you might want more salt, lemon, or a pinch of red pepper flakes.

Use immediately or transfer to an airtight container. If storing, pour a thin layer of olive oil on top to prevent oxidation.