Classic basil pesto, Pesto Alla Genovese, is by far the most popular. In fact, whenever you see the word “pesto” on a restaurant menu or in a recipe without any clarification, it is unmistakably referring to basil pesto.  There are, however, thousands of variations of pesto sauce. Pesto can be made with any leafy green instead of basil such as parsley, arugula, kale or spinach, any nuts such as almonds, walnuts, cashews, or pistachios and additions such as lemon zest, sun-dried tomatoes and even ricotta. So, let your imagination run wild!