Too Lean for Slow Cooking

• Although filet mignon is very tender, it's also among the leanest cuts of beef. While choosing a lean cut of meat may be beneficial to your waistline, this cut's lack of fat is part of the reason for keeping it out of the slow cooker. Slow-cooking filet mignon leaves the meat stringy and tough, which is the exact opposite of the desired result. Instead, choose fattier cuts of beef such as short ribs or brisket. The fat is one of the factors that keeps the meat moist while it simmers in the slow cooker.

Lack of Connective Tissues

• The tenderloin comes from one of the least used, least developed muscles in the animal. This is what makes the meat so tender, and it's also a large part of the reason that slow-cooking isn't the best method for filet mignon. Conversely, the slow cooker almost magically transforms tough cuts of beef into tender, buttery, melt-in-your-mouth meals. Slow cooking breaks down the connective tissues and collagen, causing it to melt into flavorful, fork-tender meat. Better cuts of beef for slow cooking include cuts such as chuck, which comes from the shoulder area, and round steak, which comes from the hind area of the animal.

Mild Flavor

• Slow cooking does nothing for the already mild flavor of filet mignon. While other cuts of beef, such as those that come from the neck or foreleg, develop deep flavor during the slow cooking process as the connective tissues and fat break down, since filet mignon lacks much fat or connective tissue, it doesn't benefit from this principle. Instead, the longer you cook it, the less flavorful it becomes.

The Best Cooking Methods

• To preserve the tender interior of the meat, use only dry-heat methods such as broiling, grilling, roasting or sauteing to cook filet mignon. Cook the beef over medium-high to high heat for four to six minutes per side, or until the outside is browned and the inside is pink and juicy. While the United States Department of Agriculture recommends cooking beef to a minimum internal temperature of 145 degrees Fahrenheit, meat that is less well done needs lower temperatures. If you want medium-rare meat, remove it once the internal temperature is 130 F to 135 F, or 140 F for medium.