Step 1
To a large bowl, add the tomatoes, oil, vinegar, capers, anchovies, a pinch of chile flakes, and a generous pinch each of salt and black pepper. Stir well to combine. Cover with plastic wrap and set aside to rest on the countertop if serving immediately, or in the refrigerator for 8–24 hours.
Step 2
When ready to serve, let the tomato mixture come to room temperature, stirring briefly before plating. Split each sandwich roll and top with some of the tomato mixture. Divide the burrata among the rolls. Season with salt, black pepper, or more chile flakes to taste, and serve.