Rinse the carrot tops by shaking them in a large bowl of water and draining. Then Remove the thick stems
Blanch the carrot tops: Bring a pot of water to a boil. Prepare a large bowl with ice cubes and cold water in it. Once boiling, add the carrot tops to the pot. Stir occasionally, cooking for about 3 minutes or until bright green and tender. Immediately remove from the pot, drain the hot water, and add the carrot tops to the ice cube bowl to stop the cooking process.
Drain the carrot tops, wring out excess liquid, and spread them on a plate to dry while you do the remaining recipe prep.
Add all of the ingredients from garlic through walnuts to the food processor. Blend until a chunky paste forms with small bits of carrot tops. Depending on the size of your food processor, you may need to stop frequently to scrape down the sides. Add the olive oil a tablespoon at a time until combined. Season to taste with salt, pepper, and more lemon juice if desired.