1 Put walnuts in food processor and pulse a few times.  Add the basil and pulse.  If adding garlic,  add the garlic, pulse a few times more. Add the lemon juice.

2 Slowly add the olive oil in a constant stream while the food processor is on. Stop to scrape down the sides of the food processor with a rubber spatula.  If texture is off, add stale bread soaked in water.  Add a very tiny pinch of salt and freshly ground black pepper to taste.

Serve over poached salmon, with pasta, or spread over toasted baguette slices.