Preparation Prepare barbecue (medium-high heat). Stir soy sauce and brown sugar in pie dish until sugar dissolves. Using mortar and pestle or spice mill, coarsely grind peppercorns. Dip both sides of tuna steaks in soy mixture. Sprinkle both sides of tuna generously with peppercorns, pressing to adhere. Grill tuna to desired doneness, about 2 minutes per side for medium-rare. Combine greens and radishes in large bowl. Toss with enough Caesar Vinaigrette to coat salad. Season to taste with salt and pepper. Divide salad among 6 plates. Cut tuna crosswise into thin slices; place alongside salad. Drizzle tuna and greens with remaining vinaigrette.
Preparation Prepare barbecue (medium-high heat). Stir soy sauce and brown sugar in pie dish until sugar dissolves. Using mortar and pestle or spice mill, coarsely grind peppercorns. Dip both sides of tuna steaks in soy mixture. Sprinkle both sides of tuna generously with peppercorns, pressing to adhere. Grill tuna to desired doneness, about 2 minutes per side for medium-rare. Combine greens and radishes in large bowl. Toss with enough Caesar Vinaigrette to coat salad. Season to taste with salt and pepper. Divide salad among 6 plates. Cut tuna crosswise into thin slices; place alongside salad. Drizzle tuna and greens with remaining vinaigrette.