Cut garlic cloves in half vertically and remove and discard inner green-tipped sprout. Cut garlic into small pieces, and, using a blender or mortar and pestle, crush to a paste with coarse salt. You can also crush garlic through a press and then mix with salt. Slice basil leaves and add to garlic. If using a mortar and pestle, trickle oil in slowly, working it in as for mayonnaise. If you are using a blender, add 1/3 cup oil and blend at moderate speed until you have a smooth emulsion, adding the rest gradually.

If you add cheese, stir it in by hand. Add salt as needed.

Extra pesto can be spooned into a narrow, small bowl or jar and topped with ½ -inch layer of olive oil. Cover and store in refrigerator for up to 1 week or in freezer for up to 1 month.