Tri-Tip Roast takes a dip in a flavorful marinade and then gets grilled alongside a vegetable medley (ratatouille if you're fancy).
Combine marinade ingredients in small bowl. Place beef roast and 1/3 cup marinade in food-safe plastic bag; turn roast to coat. Close bag securely and marinate in refrigerator 15 minutes to 2 hours, turning occasionally. Cover and reserve remaining marinade in refrigerator.
Remove 1/4 cup of reserved marinade for ratatouille; set aside. Toss vegetables (except tomatoes) with remaining marinade.
Remove roast from marinade; discard marinade. Place roast in center of grid over medium, ash-covered coals or over medium heat on preheated gas grill; arrange vegetables (except tomatoes) around roast. Grill roast, covered, 25 to 35 minutes for medium rare (145°F) to medium (160°F) doneness, turning occasionally. Grill eggplant and bell peppers 7 to 11 minutes; zucchini and yellow squash 8 to 12 minutes (on gas grill, eggplant 6 to 8 minutes; bell peppers, zucchini and yellow squash 7 to 11 minutes) or until tender, turning occasionally.
Remove roast when instant-read thermometer registers 135°F for medium rare; 150°F for medium. Transfer roast to carving board; tent loosely with aluminum foil. Let stand 10 minutes. (Temperature will continue to rise about 10°F to reach 145°F for medium rare; 160°F for medium.)
Meanwhile, cut grilled vegetables into 1-inch pieces. Combine vegetables, tomatoes, basil and reserved 1/4 cup marinade in large bowl; toss to coat. Carve roast diagonally across the grain into thin slices. Season roast and ratatouille with salt and black pepper, as desired. Serve roast with ratatouille.