Few foods embody the Mediterranean summer better than pesto, a traditional Ligurian herb paste and pasta sauce that perfectly blends the diverse fragrances and flavors of this land. Pesto can be made very easily - and cheaply - at home. You can adjust the flavorings to your own tastes, and even grow its chief ingredient - basil - in your garden or in pots on your terrace: just 6 to 10 basil plants, planted correctly, will grow into bushes that yield a nice weekly crop, enough for a weekly supply of pesto over the summertime.
Traditional pesto is made with ingredients that are the essence of the Italian peninsula: the leaves of basil, a Mediterranean aromatic plant (there is also a very local Genovese basil variety); garlic; olive oil; Parmesan or pecorino cheese; and the seeds of the Umbrella Pine, a Mediterranean evergreen.
Pesto is easy to make, and is the perfect summer sauce for pasta and lasagna, as well as a tasty spread on bread. It keeps for several days in the refrigerator, and can also be frozen. Homemade pesto doesn't have the emerald green color of store-bought pesto, because what you buy in stores has added antioxidants. Basil, in fact, oxidizes easily, but with a few precautions you can reduce its natural darkening.
~ HOW TO MAKE PESTO FROM YOUR HOME-GROWN BASIL ~
40 fresh basil leaves
1 handful of pine nuts
1 clove of garlic
5 tbsp grated Parmesan (or 4 tbsp Parmesan and 1 tbsp pecorino)
salt
extra-virgin olive oil
(Quantities are from a recipe from this local cuisine book. Once you've made pesto a few times, you'll find that you really don't need to refer to a recipe at all, and can start improvising based on your own tastes and ingredients.)
~ Growing and harvesting basil - 40 fresh basil leaves 
Growing Season:
Basil is an annual aromatic pant, and can be grown surprisingly easy at home, if you follow a few basic rules. Basil must have a full-sun exposure, and be sheltered from wind. Also, it doesn't do well if nighttime temperatures dip below 50F (10C), so if you grow it outdoors, plant it well past the last frost date, and harvest it when the summer temperatures begin to decline.
Spacing:
Basil can grow into a fairly tall, bushy plant, but it needs space - 6" (15 cm) between plants - and if you buy it in pots you must divide the little plants before transplanting them.
You'll find more information on how to grow basil from seeds and/or indoors here.
Harvesting:
Harvesting basil when it reaches a height of 4" (10cm) strengthens the plant. Always cut off the top of the plant and of the larger branches when the little side leafy shoots start to appear - this encourages the growth of more leaves, and soon your basil plant will become a vigorous bush.
Whenever you see a flower beginning to grow - green at first and shaped almost like little leaves - prune it immediately. Flowering will inevitably happen by the end of summer, but you want your plant to grow and produce leaves as long as possible!
When you plants have grown to about 8" - 20cm long, and have become generous bushes with lots of side branches, you can start harvesting the larger leaves as well.
Washing and storing leaves:
Wash and dry basil leaves, handling them gently because they bruise easily. If you don't use them immediately, you can store them for a couple of days in the refrigerator in an air-tight container, a damp paper towel placed at the bottom for moisture. (Otherwise they wilt.)
~ Pine Nuts - one handful
Umbrella pines produce roundish pine cones full of oblong little nuts. They are small, with a soft, buttery texture, a delicate aroma, and an almost sweet taste. They are expensive in stores, but are an essential ingredient in pesto. (I've had pesto made with other nuts - cashews and walnuts are a common substitutes - but they just aren't as good.) You only need a handful to make pesto; refrigerate the rest or they may go rancid. (You do not toast pine nuts for pesto.)
~ Garlic - one clove
~ Parmesan - 5 tbsp grated
~ Extra-virgin olive oil
A little olive oil goes into the pesto as it's being made, but mainly the oil is used in storing the paste, and drizzling over the pasta at meal time.
~ Making pesto
Traditionally, pesto was made by pounding the ingredients with a wood pestle in a mortar of Carrara marble (available here). There is a reason for this: pounding tears up the leaves and releases the essential oils in the basil, bringing out its full flavor.
Mixing ingredients:
Otherwise, though, use an electric mixer - not so traditional, but much handier. First grind the pine nuts finely. Then add grated Parmesan (I actually add it in little cubes and let the mixer do the grating), garlic, basil, a little olive oil, and a pinch of salt, and mix until you get a thick paste.
Storing:
You can either freeze your pesto, or store it in an air-tight container in the fridge. In the latter case, press the pesto down into the container so no air bubbles are left inside it, and pour over enough olive oil to cover it completely: the oil helps prevent oxidizing and acts as a natural preserving agent. Pesto keeps up to a week in the fridge.
~ Trofie al pesto
Fresh trofie, a thin and twisted shaped pasta, is the traditional accompaniment for pesto. Whatever pasta shape you use, just before you drain it, scoop out some of the cooking water with a ladle and stir it into your pesto paste, to make a creamy sauce. Stir this pesto sauce into your drained pasta, drizzle olive oil over the top, and serve it up hot!
Rebecca loves pesto. These summer days, she has it for breakfast, spread on my home baked bread, and for dinner too with the rest of the family. I'm making pesto every 5 days or so. In September, before my basil starts suffering from cool night temperatures, I think I'll make and freeze a large batch of pesto, in one-meal portions, which will last me well into the winter!
If you haven't already, check out Kasia's post on pesto - she tells some nice stories about this great dish.
