In a food processor, add the basil leaves, chopped garlic, oil, and parmesan cheese.
Close tightly and blend until smooth.
Continue to add more cheese and/or oil to your desired consistency: smooth in texture with minimal to no clumps of garlic or basil leaves.
Serve as desired (sandwiches, pastas, pizzas, salads, etc.)
Notes
Add some fresh squeezed lemon to the pesto for added acidic flavor. Plus, a lemon pesto is absolutely delicious on fish and in pasta recipes.You might need to add in more oil, more cheese, or more basil as you blend the ingredients together to make it creamy and smooth. If you like it more rustic, don't add more cheese!