Pistou

In a mortar, pound the garlic cloves with the coarse salt until a completely smooth, white paste forms. The salt crystals act as an abrasive and draw out the moisture from the garlic. This step is crucial — any remaining garlic chunks will make the sauce harsh and unpleasant. If using a food processor instead, mince the garlic as fine as possible before proceeding.

Add basil leaves to the mortar in two or three batches. Pound and grind with a circular pressing motion — not sharp strikes — until each batch is completely incorporated before adding the next. The goal is to bruise and crush the cells to release the oils, not to create friction heat. If using a food processor, pulse briefly in short bursts — blending too long heats the basil and turns it black.

Stream in olive oil a little at a time, stirring and pressing the paste against the sides of the mortar to incorporate. The sauce will loosen and become glossy as the oil emulsifies with the water content of the basil. Add a small squeeze of lemon juice if using. The consistency should be thick enough to coat a spoon but fluid enough to pour. Use immediately — pistou begins to oxidize and lose its vivid color within 30 minutes.