At holiday time, I like to roast. But like most cooks, I worry about two things: undercooking and overcooking. Luckily, I've found a device that ensures perfect results: the Polder Preprogrammed Cooking Thermometer. It's great for cooks — seasoned pros and nervous novices alike — who want to keep an eye on things, because the probe goes into the roast and the thermometer, which is connected to the probe by a wire, stays outside of the oven. Just select the type of meat you're roasting — chicken, pork, turkey, beef, lamb, or veal — and if it's one of the last three, decide how well you want it done. The thermometer's digital readout lets you monitor the meat's internal temperature, and when the right temperature has been reached, an alarm sounds. Best of all, you can customize the settings. Do you disagree with the USDA's opinion of what medium-rare beef is? No problem. Tell the Polder what temperature you want, and it won't forget. You can use the Polder for foods that haven't been preprogrammed — fish, for example — by setting the temperature manually before cooking. The Polder Preprogrammed Cooking Thermometer retails for $35. Visit Polder on the Web (www.polder.com).