enough oil to lightly coat the surface of pan, unless you are using a very fatty meat
Myths abound about the benefits of searing, most notably that it seals in the juices. In reality, searing or browning meat or fish creates a caramelized, golden crust that adds texture and a depth of flavor.
The most important factor in this technique is to start with a very hot pan. Ideally, you should use one made from a stainless steel or anodized metal – a heavy material that will conduct and distribute heat evenly and well.
Although you can use nonstick pans for delicate fish, pans without a nonstick finish do a better job of browning, and leave lovely browned flavorful bits to use in a pan sauce (see “Making pan sauce.”)
To brown, heat a completely dry pan, then add enough oil to lightly coat the surface (if you’re using meat that has a lot of fat, you can skip this step and put it directly into the dry pan). The oil should heat to the point where it shimmers, but does not smoke. You can test this by flicking a droplet of water into the pan – if the pan is ready, the water should sizzle and evaporate upon contact.
Place your ingredient directly into the pan. It will hiss at first, but let it cook until a golden brown crust forms. If the pan is heated properly, the ingredient won’t stick to the pan, and you’ll be able to lift it with tongs or a spatula easily.
Keep in mind that if you overcrowd the pan, the ingredients will steam rather than brown, so sometimes you’ll need to cook in batches. It’s OK to wipe out the pan in between, but leave the fond – the brown bits that stick to the bottom.
Read more: http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/07/09/FDTA11HHDM.DTL#ixzz0enlHG0MB