Filet Mignon and Porterhouse Steak are both cuts of beef, but have a few differences.
The Filet Mignon is cut from the tenderloin, which is located in the short loin area near the ribs. It's one of the most tender steaks available because it has less connective tissue than other cuts, resulting in a very mild flavor and buttery texture. Filets generally range between 6-12 ounces per steak.
The Porterhouse Steak comes from the back end of the short loin where it meets up with the sirloin section. This steak is larger than filets usually ranging between 12-20 ounces depending on its size and thickness. The porterhouse contains a larger portion of tenderloin and has more flavor than the filet mignon due to its marbling. It also has a greater amount of connective tissue, which makes it tougher but more flavorful.
Both steaks are best cooked over high heat with minimal seasoning in order to bring out their full flavor. The main difference between the two is that Filet Mignon is more tender and milder in flavor while Porterhouse Steak is larger, fattier, and more flavorful due to its higher fat content.