Rinse basil, discard big central stems, and pat dry. Crush garlic with your preferred method. Lightly toast pine nuts or walnuts in a dry skillet or on a baking sheet in an oven at 350 for 5-10 minutes. (With either method, be sure to move the nuts around often - they burn easily. They're done when the outside is brown, not black, and they taste good!)
Combine basil, salt, garlic, nuts and about 1/4 cup of the oil in a food processor or blender, or smush together by hand. Add the rest of the oil gradually as the smushing/processing continues. Store in the fridge or freeze!