Prepare the Ingredients

1. Peel and Crush the Garlic: Use a mortar and pestle to crush the garlic cloves with sea salt until it forms a paste. If you don’t have a mortar and pestle, finely mince the garlic and mash it with the salt using the back of a spoon.
2. Wash and Dry Basil Leaves: Rinse the basil under cool water and pat dry with a clean kitchen towel. Ensure the leaves are free of moisture to prevent a watery pesto.

Combine Ingredients

3. Add the Basil Leaves: Gradually add the basil leaves to the mortar, crushing them until they release their oils and form a green paste. (Alternatively, use a food processor, pulsing in short bursts.)
4. Incorporate the Cheeses: Add the Parmesan and Pecorino cheeses to the mixture and continue crushing or pulsing until smooth.
5. Add Walnuts and Nutmeg: Toss in the walnuts and a pinch of nutmeg, crushing or blending until well integrated. The texture should be slightly coarse but uniform.

Finish with Olive Oil

6. Drizzle in Olive Oil: Slowly add the olive oil while stirring continuously to emulsify the pesto. The consistency should be smooth but not overly runny. Adjust the amount of oil if necessary to reach your desired texture.

Tips for Success:

• Using a Mortar and Pestle: Traditional pesto has a more textured, rustic feel when made this way. Crush ingredients in small batches for best results.
• Food Processor Option: If time is short, a food processor works well, but pulse gently to avoid overheating the basil, which can alter its flavor.
• Ingredient Substitutions: Don’t have walnuts? Swap for almonds, cashews, or the traditional pine nuts. Each nut gives a unique flavor profile.
• Oil Quality Matters: Use a high-quality, cold-pressed olive oil for a rich, aromatic pesto.
• Cheese Choice: Parmesan adds nuttiness, while Pecorino gives a sharper, saltier edge. Adjust ratios to your taste.

Storing and Serving:

• Refrigeration: Store in an airtight container, covering the surface with a thin layer of olive oil to prevent oxidation. Keeps for 3–5 days in the fridge.
• Freezing: Freeze in small portions (e.g., ice cube trays) for up to 3 months.
• Serving Ideas: Toss with pasta, spread on sandwiches, drizzle over grilled vegetables, or swirl into soups.