1Pour water and lemon juice over the bread crumbs; let stand for about 5 minutes until the bread absorbs all the liquid and becomes mushy. In a blender or food processor, mix the soaked bread until it turns into a paste. With the motor running, drizzle in warm melted butter as thin a stream as possible and process until mixture thickens slightly. Taste and add salt if necessary. Add basil leaves and pulse a few times until the basil is chopped and incorporated.