A small separate muscle on the underside of the breast, not a strip cut from it. More tender than the breast proper, with a tough white tendon running down its length that has to come out.
The tenderloin is the pectoralis minor, lying against the breastbone underneath the main breast muscle. It's a distinct muscle with its own membrane, not a piece cut off the breast, and it's noticeably finer-grained and more tender because it does less work. Each bird yields two, about two ounces each. A white tendon runs from one end nearly through the whole length; it's elastin, it does not soften at any temperature, and left in it makes the tender chewy and pulls it into a curve as it heats. Most commercially sold tenders still have it.
The same lean white muscle as the breast, with the same problems in a smaller package — under 2% fat, no collagen, and water loss accelerating past 155°F. The difference is size: a tender is thin enough to cook through in three or four minutes, which means the margin between done and dry is smaller in time even though the temperature target is identical. A brief brine helps more here than on a breast, because there's so little thermal mass to buffer anything. The fine grain also means it takes on marinade and breading well and shreds cleanly for salads.
The classic use, and the coating insulates a very lean thin muscle from the oil while adding the texture it lacks.
HowBrine thirty minutes, dry, then flour, egg, panko. Fry at 350°F for three to four minutes until golden and 155°F inside. Rest two minutes.
Small and thin enough to cook through in a hot pan before the outside dries, provided they're not crowded.
HowDry, salt, hot pan with oil, two minutes a side. Pull at 155°F, rest. Crowding drops the pan temperature and steams them grey.
Their shape suits a skewer, and direct heat is fast enough to beat the drying curve.
HowMarinate thirty minutes to two hours, thread lengthwise, grill over high direct heat two minutes a side.
Gentle moist heat is the most reliable way to keep a lean muscle moist when it's going to be eaten cold.
HowBarely simmering seasoned water or stock, eight to ten minutes off the heat with the lid on, to 155°F. Cool in the liquid and shred.
The white tendon running the length of a chicken tender is elastin, which unlike collagen does not convert to anything at any temperature you can reach in a kitchen — it stays a tough cord, and worse, it contracts as it heats and curls the tender into a bow so it cooks unevenly. It's the reason breaded tenders sometimes have one chewy strand through the middle. Removal takes seconds: grip the exposed end with a paper towel, lay a fork over the tender with the tendon through the tines, and pull. It comes out whole. Almost all commercially packed tenders still have it, and almost no recipe mentions it.
Sold separately as tenders or tenderloins, usually at a premium over breast despite being trim from the same bird. Buying whole breasts and pulling the tenders off yourself is cheaper and gives you both. Look for pale pink, firm meat with no liquid pooling. Check whether the tendon is present — it almost always is. Avoid anything labelled tenders that's actually breast cut into strips, which is a different and less tender product sold under the same word. Air-chilled birds give firmer meat. Four to six tenders per person.
Doneness: 155-157°F, pulled and rested to about 160°F. They're small, so total cooking time is three to four minutes by any method. Past 165°F they're noticeably dry.
No, though a lot of what's sold as tenders is exactly that. The real tenderloin is a separate muscle — the pectoralis minor — lying underneath the breast, finer-grained and more tender, with its own membrane and tendon. Breast cut into strips is a fine product but it's a different, slightly tougher one. The tell is the tendon: real tenders have it, strips don't.
Hold the exposed white end with a paper towel for grip. Slide a fork so the tendon sits between two tines with the meat on the other side, press the fork down against the board, and pull the tendon through. It comes out in one piece in about two seconds. A knife works too but wastes meat.
Almost always crowding or overshooting. A tender has very little thermal mass, so a crowded pan drops below searing temperature and they steam, and even correctly seared they pass 165°F within thirty seconds of hitting 155°F. Cook in batches, and pull them earlier than feels right — they carry over several degrees.