Adapted from Ashley of The Edible Perspective:

1/2 cup raw walnut pieces
2 cups tightly packed fresh basil Leaves
2 small garlic cloves
1/4 cup water

Salt and PepperCombine walnuts, basil and garlic in a food processor or high speed blender and process/blend until well-mixed.  With the motor running, stream water through feed tube until pesto comes together in a smooth and thick sauce, adding more water if desired.  Season to taste with salt and pepper.