Pesto tastes like the herby, green essence of summer in a bowl, whether you twirl pasta in it, spoon it over grilled vegetables, dollop it into minestrone, or serve it as a dipping sauce alongside seared shrimp. This is a classic version of basil pesto, albeit made in a food processor instead of with a mortar and pestle. Be sure to add the oil slowly, so it emulsifies the sauce. Use this recipe as a baseline for the amount and type of pesto you prefer, and adjust it to your needs. You can cut this recipe in half for a smaller amount, or make extra; this recipe is easily doubled or tripled, and leftovers will keep in the refrigerator for up to five days when topped with a layer of oil to prevent the pesto from oxidizing. If you are making a large batch of pesto to stash in the freezer, omit the cheese for now and add it when you are ready to thaw and use the sauce. You can also customize this recipe with different nuts, greens, cheese, and oil. Swap in walnuts, pecans, or pistachios for the pine nuts, and use parsley, arugula, or blanched kale in addition to or instead of basil. A sharp cheese like Cheddar or Gruyère can be subbed in for the Parmigiano-Reggiano, and avocado or nut oil can be used as alternatives to olive oil. You can further make this sauce your own creation by stirring in a pinch of smoky chile powder, black pepper, crushed red pepper flakes, or grated lemon zest after blending the pesto.