Basil pesto is always a favorite, but other herbs, such as thyme, mint, tarragon, and even arugula, prove to be wonderful variations as well. Consider mixing up your own unique batch of pesto with various herbs and nuts, including walnuts, peanuts, and cashews. The more Parmesan cheese you use, the more flavorful the pesto will be but it will also be less green. Makes about 1 1/2 cups.