Whisk the marinade ingredients together in a small bowl.
Place the steaks in a resealable plastic bag.
Pour the marinade over the steaks. Refrigerate marinating steaks for at least 2 hours.
Remove marinating steaks from the refrigerator and let sit at room temperature for 30 minutes before grilling.
Heat grill to medium heat. Add remove steaks from marinade and place on a hot grill.
Grill steaks for approximately 8 minutes on each side, turning only once. Internal temperature of the steak should reach 140 degrees (use a meat thermometer).
Heat olive oil in heavy large saucepan over medium heat, make sure the olive oil doesn't turn brown. Add garlic and sauté until a light golden brown, about 5 minutes.
Add tomatoes, basil sprigs, and dried crushed red pepper to a food processor and pulse a few times. Add tomato mixture to the garlic in the sauce pan.
Bring to a simmer. Reduce heat to low and simmer until mixture is reduced to a thick sauce consistency (about 3 cups), stirring occasionally, about 15 minutes.
Season sauce to taste with coarse kosher salt and freshly ground black pepper.
Top grilled steaks with tomato basil sauce. Garnish with shredded basil.