Take a large pan and set over medium-high heat. Add bacon and cook until fat renders 2 to 3 minutes. Add the smashed garlic clove, thyme sprigs and Brussels sprouts and cook gently until slightly caramelized. Add stock and reduce heat to a simmer. Season with salt and a little pepper, cover and simmer for 12 to 15 minutes until tender. Remove lid and add a splash of vinegar and reduce until syrupy, 2 to 3 minutes.
After Brussels sprouts are done cooking, put them in oven safe dish. In sheet tray and toss bread crumbs with rosemary, thyme leaves and chopped garlic, then drizzle with a little olive oil and salt and pepper. Sprinkle bread crumb mixture and Parmigiano over Brussels sprouts and bake in a hot oven until golden and crispy.