Preheat the grill to medium-high heat. I like it to be around 500 degrees.
Slice the peppers down the center, cutting them in half from top to bottom. Remove some of the ribs and seeds. Spray or brush the peppers with olive oil. Sprinkle with salt and pepper.
Make the vinaigrette. In a bowl, whisk together the vinegar, garlic, a pinch of salt and pepper, crushed pepper flakes until combined. Whisk in the olive oil until emulsified.
Make the sourdough crumbs. Heat a skillet over medium heat and add the butter. Add in the torn sourdough pieces with a pinch of salt and pepper along with the garlic powder. Cook, tossing often, until crunchy and golden, about 5 to 6 minutes.
Place the peppers on the grill, cut side down. Grill for 5 to 6 minutes (or until golden and slightly charred), then flip and grill for another 5. Remove the peppers and place them on a dish. Drizzle them with a bit of the vinaigrette and let them sit for a few minutes to marinate in the dressing. Tear apart a ball of burrata and distribute it over the peppers. Drizzle on more vinaigrette. Top with the sourdough crumbs and fresh herbs.