Here's my recipe for pesto--a variation of a number of recipes that I've tried over the years. Truth be told, I don't even measure any more.
3 cups fresh basil leaves
3 cloves of garlic (or to taste)
1 cup walnuts (or pine nuts)
1 cup freshly grated parmesan cheese
3/4 cup good quality olive oil
salt and pepper to taste
Pulse the garlic and nuts a few times. Add the basil and process until well chopped together. If you are going to use the pesto within a few days, add the cheese now. If you plan to freeze the pesto, add the cheese when you have defrosted and are ready to use. With the processor running, slowly add the olive oil until the consistency you desire. Add salt and pepper to taste.