In a small bowl, stir together the olives, parsley, oregano, vinegar, salt, red pepper flakes, garlic, and 2 Tbsp of water. Stir in the olive oil and set aside.
Preheat a grill to medium-high heat, if using.
Preheat a small cast-iron pan on the grill grate, or preheat on the stovetop over medium-high heat. When the pan is hot, add the cheese.
Cook until the bottom of the cheese begins to brown, about 2 minutes. Carefully flip the cheese with a spatula and cook until the second side is browned and the cheese is beginning to ooze, 2 to 3 minutes. (Alternatively, finish the cheese by putting it under the broiler until soft and golden, about 5 minutes, or bake in a 425°F [220°C] oven for 10 minutes.)
Transfer the cheese to a platter and serve immediately accompanied with the bread and chimichurri.
