Begin by preparing your radish tops. Rinse them thoroughly under cool water to remove any dirt. Shake off excess water and then gently dry them with a clean towel. It’s vital to ensure they are completely dry for the best texture in your pesto.

Add the freshly washed radish tops, garlic, sliced almonds, Parmesan cheese, and lemon zest to a blender or food processor. It's like a vibrant green party in there! Make sure not to overfill; you may need to do this in batches depending on your equipment's size.

Turn on the blender or food processor. Pulse and blend until the mixture becomes a coarse paste. You don’t want it to be totally smooth right away; some texture adds character.

With the blender running, slowly pour in the extra-virgin olive oil. This helps to emulsify the mix. Then, squeeze the juice of half a lemon into the pesto. Blend until the pesto reaches a creamy consistency.

Once blended, taste your creation. Add salt and freshly cracked black pepper as you see fit. A little taste adjustment can go a long way. If it feels too thick, you can add a hint of water or more olive oil to achieve your desired consistency.

Scoop your prepared pistou radish leaf pesto into an airtight container. Cover the surface with a thin layer of olive oil to help prevent browning. Store in the fridge, where it will keep fresh for about a week.