Heat the olive oil in a heavy pot over medium heat. Add the whole garlic cloves and let them sizzle for about 1 minute to perfume the oil. If the cloves are peeled, remove them before they start to brown. If the cloves still have their skins on, you can leave them in.
Add beef chunks and brown on all sides.
Season with salt, crushed black pepper, whole peppercorns, and bay leaves. Stir to coat the beef.
Pour in the entire bottle of Chianti and bring to a gentle boil.
Cover and simmer on low for two hours., or until the beef is fork‑tender but still holds its shape.
Uncover the pot, remove and discard the bay leaves and garlic, then simmer uncovered for 5 to 8 minutes, until the sauce reduces and turns glossy.
Remove peppercorns if needed and serve.