Preheat oven to 425° F. Drizzle exposed cloves of garlic with olive oil, season with salt and pepper and wrap in foil pouch. Roast about 40 minutes until very soft and tender, caramel in color. Cool to handle.
For filling, heat olive oil, 2 turns of the pan, in Dutch oven or heavy pot over medium high heat, add guanciale or pancetta and lightly brown, 2 minutes, add beef and caramelize, browning meat to develop sugars, add salt and pepper, carrots, celery, onions and 1 bulb of roasted garlic, squished from skins, stir well to incorporate garlic, add bay and herb bundle and partially cover, cook 10-12 minutes to soften, stirring occasionally, over medium heat. Stir in tomato paste until fragrant, 1-2 minutes, add wine, stock, 1 cup milk, bring to bubble, reduce heat and simmer gently.