Roast the Garlic (Optional): If you choose to include roasted garlic, start by roasting the garlic in the oven.
Prepare the Dip: In a food processor, combine the roasted garlic (if using), cannellini beans, and boiling water. Process until the mixture begins to smooth out. Incorporate the lemon juice and olive oil, continuing to blend until the dip reaches a smooth and creamy consistency. If the dip appears too thick, gradually add more boiling water until you achieve the desired texture.
Cook the Pancetta: Heat a skillet over medium heat and cook the pancetta until it is crispy. Once done, transfer the pancetta to a plate lined with kitchen paper to drain the excess oil.
Toast the Nuts: In the same skillet, add the hazelnuts and pine nuts, cooking them until they are golden and aromatic. Transfer the nuts to the same plate as the pancetta to remove any excess oil.
Assemble the Dip: Transfer the prepared bean dip into a serving bowl or plate. Sprinkle the crispy pancetta, toasted nuts, and chopped rosemary evenly over the top.