Balsamic Grilled Steak with Buttery Tomato Sauce

Ingredients

• 3 garlic cloves (grated on a microplane)
• ¼ cup balsamic vinegar
• 1 tablespoon Dijon
• 3 tablespoons extra-virgin olive oil
• ½ teaspoon red pepper flakes
• ¼ teaspoon dried rosemary
• 1 teaspoon brown sugar
• 1 teaspoon Worcestershire
• Kosher salt
• Freshly ground black pepper
• 1 lb. hanger steak
• 24 cherry or grape tomatoes (stems removed, if any)
• ¼ teaspoon sugar
• ¼ teaspoon dried thyme
• 1 tablespoon unsalted butter
• Fresh basil leaves (roughly torn, to taste)