Lemon Grilled Beef with Basil Vinaigrette

2 pounds Beef trip-tip bottom sirloin roast or...1 1/2 pounds Top sirloin steak, 1 1/4 inch thick
3 Red or yellow bell peppers

SEASONING ---
1 tablespoon Lemon peel grated
1 1/2 teaspoons Ground cumin
1/2 teaspoon Black pepper
1/2 teaspoon Salt

VINAIGRETTE -
1/2 cup Water
2 tablespoons Balsamic vinegar
2 tablespoons Fresh basil leaves chopped
2 teaspoons Dijon style mustard
1 Garlic clove finely chopped

Combine seasoning ingredients; reserve half of mixture for vinaigrette. Trim fat from beef roast. Press remaining seasoning mixture evenly into surface of roast. Place roast on grid over medium coals. Grill, turning occasionally, 30 to 35 minutes (20 or 28 minutes for top sirloin) for medium-rare to medium doneness. Remove roast when meat thermometer registers 140 F for medium-rare, 155 F for medium. Let stand 10 minutes before carving.

Meanwhile, in a medium bowl, whisk water, vinegar, basil, mustard, garlic and reserved seasoning mixture; mix until blended. Cut sides off peppers in 3 or 4 pieces, following natural contours. Brush vinaigrette over peppers, reserving some vinaigrette for use as a sauce. Grill peppers along with beef until lightly browned, about 8 to 10 minutes, turning once. Carve roast across the grain into thin slices. Arrange beef and peppers on serving platter; drizzle with reserved vinaigrette. If desired, garnish with basil sprigs.