In a medium-size bowl, combine tomatoes, garlic, olive oil, vinegar, salt, pepper and basil. Cover and refrigerate for 20 minutes.
Heat oven to 450°. Coat a 15 x 10 x 1-inch baking pan with nonstick cooking spray. Place potatoes in the baking pan and toss with 1 tablespoon of the olive oil. Season with salt and pepper. Bake at 450° for 20 minutes, stirring once, or until fork-tender.
Heat remaining tablespoon olive oil in a large nonstick skillet over medium-high heat. Season both sides of steaks with Montreal steak seasoning. Sauté meat in batches, for 2 minutes, then turn and sauté for an additional 1 to 2 minutes, until medium-rare.
Serve steaks immediately with roasted potatoes and tomato salad.