Toast almonds in a dry pan for about 5 minutes, tossing frequetly and making sure it doesn't burn.
Set aside to cool.
Add basil, nuts, lemon juice, garlic, salt and peper to a food processor or a high speed blender.
Start pocessing on a medium speed and drizzle in the olive oil in a slow steady stream.
Stop the machine when the olive oil is all mixed in, scrape down the sides of the bowl and contitue processing until you reach a desire consistency.
Add more olive oil if pesto is too thick.