No matter what your recipe says, the best way to tell if meat is cooked is to use a meat thermometer. These are generally used with larger cuts of meat - such as roasts - or with whole chickens or turkeys.
Push the meat thermometer into the thickest section of the meat you are cooking before you place the meat in the oven.
Make sure the thermometer is not touching bone, but is embedded deeply in the meat itself.
Put the meat in the oven at the recommended temperature.
Leave the meat thermometer in the meat throughout the cooking process.
Check the meat thermometer as soon as the recommended cooking time for the cut of meat you are preparing is almost finished. The reading on the thermometer - check the levels for the kind of meat you are cooking - will indicate when the meat is cooked throughout.
Meat thermometers come in a variety of styles, including dial types, probes and stand-up types of thermometers. Some probe thermometers allow you to connect the thermometer to a countertop unit that gives you the temperature reading without having to open the oven. Microwave-safe meat thermometers are also available. Get a meat thermometer that is dishwasher-safe for easy cleaning. Meat thermometers can be used for things other than measuring the temperature of meat. Some can - for example - check the temperature of water to be sure it's safe to add yeast, or check the internal temperature of warmed-over leftovers to be sure they're safe to eat.
A meat thermometer gets hot in the oven. Use care when reading it or removing it after the meat comes out of the oven.