This is one sexy sandwich. A flaky light croissant joined with slices of  tenderly cooked brisket, melted horseradish cheese and a thin spread of dijon makes quite a statement. Brisket, one of the eight beef primal cuts, is muscle meat and should be cooked slowly and kept moist for tender sandwich eating. Brisket contains a lot of fat which helps to keep it from drying out during cooking. Slice thin strips and remove the fat. Layer a slice of horseradish cheese over the brisket and place under the broiler for two minutes. Horseradish cheese gives the sandwich punch along with the right mustard. Have you tried green tomato pickles? Wonderful flavor to complement this sandwich. Slice them and serve them atop of the sandwich or on the side.