Whisk oil, lemon juice and garlic in small bowl. Season with salt and
pepper. Place steak and squash in shallow pan. Pour half of
vinaigrette over. Turn steak and squash to coat. Let stand at room
temperature 20 minutes.

Prepare barbecue (medium-high heat). Season steak and squash with
salt and pepper. Grill steak and squash until steak is medium-rare
and squash is tender, about 3 minutes per side. Remove squash from
grill. Transfer steak to cutting board and thinly slice across grain.

Divide spinach between 2 plates. Place tomato wedges on 1 side of
plate. Place steak in center of plate. Drizzle with any accumulated
juices. Place squash on side of plate opposite tomato wedges. Drizzle
squash and tomato with remaining vinaigrette and serve.