Add the basil leaves, garlic cloves, Parmesan cheese, pine nuts and salt to a food processor.

Start the processor and drizzle in the olive oil, process until a smooth paste consistency.

If freezing, add pesto in 1/2 cup portions to plastic freezable containers then top it with a thin layer of olive oil so that none of the pesto is open to air. The pesto will maintain its vibrant green color, otherwise it will turn a dark grayish color.