Among other things, summertime is about eating yourself stupid on fresh vegetables and fruit from the farmer's market.
1 large bunch basil
4 cloves garlic
1/3 c (pre-grating) freshly-grated, extra-good Parmesan or Romano
1/3-1/2 c. pine nuts
High-quality extra-virgin olive oil
Red wine vinegar (optional)
I like rougher pesto; the smooth stuff just doesn't do it for me.
So here's what you do: go to Sam's Club, Costco, or what have you, and buy a block of Parmegiano-Reggiano and a package of pine nuts. Don't bother buying this stuff at a grocery store; you'd be stingy with it, and that would be sad.
(Do you really need the pine nuts or cheese? Well, no, you could make pesto without them, but it wouldn't be sublimely yummy; it would be chopped basil - you would be better off just snipping basil leaves into your dish at the last second, to save time and sparkly basil freshness. Pesto is greater than the sum of its parts.)
Then go to the farmer's market and buy a bunch of basil, a big one that masses about as much as a bunch of leaf lettuce. Or two or three bunches of basil, if you want to freeze some pesto for winter (this works very well; see below). Get some fresh garlic, while you're at it. It should go without saying that if you can't use fresh garlic or basil, don't bother; get pre-made pesto in a jar instead.
Strip the basil leaves off the larger stems and wash the leaves thoroughly. Drain and drip dry.
Pull out your trusty nut chopper, the one with the springs and the W-shaped blade. Or a food processor, I guess. A blender is right out. Chop the leaves into largish flecks without pureeing them - standard crossword-puzzle box size or so. If you care whether your basil turns dark, I suppose you could chop it by hand - I'm too lazy.
Crush about 4 cloves of garlic through a garlic press and stir into the basil.
Grate (use a Microplane-style fine grater, if you have it) about 1/3 cup of Parmesan into the basil mixture.
Put about 1/2 to 3/4 cup of pine nuts in a dry saute pan, and toast the nuts over medium heat, stirring frequently, until they are brown. Chop the nuts and add.
Start adding the best extra-virgin olive oil you can find. Add enough oil so the basil clings together smoothly in a paste (think tomato paste, only not as stiff), about 1/4 cup. If you like, add a few tablespoons of red wine vinegar (I know, I know, it's not standard).
The flavor should be fairly mellow, except for the garlic. That's okay. The best way to bring out the full flavor of the pesto is with a gentle heat - add the pesto to hot dishes AFTER you pull them off the heat.
To freeze: fill an ice cube tray with pesto and freeze, then pop the block out and put them in a freezer bag, removing as much air as possible (to prevent freezer burn).
Angel hair with pesto and tomatoes
1 recipe of pesto (see above)
3-4 good-quality ugly tomatoes, chopped to bite-size and seeded
1 lb. angel-hair pasta
Cook pasta al dente in WELL salted water and drain, reserving a little pasta water. While still hot, toss with pesto and tomatoes, adding a little pasta water if it's too dry. Top with feta and capers, if desired.