MUSTARD-SEED-CRUSTED BURGERS WITH HORSERADISH SLAW

Steps:

• Whisk mayonnaise, sour cream, and horseradish in medium bowl to blend. Season with salt and pepper. Form ground beef into four 1/3-pound burgers, each about 3 3/4 inches in diameter and 1/2 inch thick. Sprinkle both sides of burgers with salt and pepper. Spread mustard seeds on small plate. Press both sides of burgers firmly into mustard seeds.
• Heat vegetable oil in heavy large skillet over medium-high heat. Add burgers and cook until brown on both sides and pink in center, about 4 minutes per side. Arrange roll bottoms on each of 4 plates. Transfer burgers to roll bottoms. Stir lettuce into horseradish mixture to coat. Divide lettuce mixture atop hamburgers. Cover each burger with roll top and serve.