Preheat the oven to 400°F or 200°C.
Remove the loose papery layers from the garlic bulb, keeping the cloves attached.
Slice off the top of the garlic bulb to expose the cloves. Drizzle with 1 tablespoon of olive oil and wrap the bulb tightly in aluminum foil.
Place the wrapped garlic on a baking sheet and roast for 35–45 minutes, or until the cloves are soft and golden.
Allow the roasted garlic to cool slightly, then squeeze the softened cloves from their skins.
Add the drained white beans, roasted garlic, chopped rosemary, lemon juice, lemon zest, sea salt, black pepper, and remaining olive oil to a food processor.
Blend until smooth and creamy, scraping down the sides of the bowl as needed.
Add warm water or vegetable broth, 1 tablespoon at a time, until the mixture reaches your preferred consistency.
Taste and adjust the seasoning. Add more lemon juice for brightness, rosemary for extra fragrance, or salt and pepper as needed.
Transfer the white bean mixture to a serving bowl.
Garnish with olive oil, fresh rosemary, lemon zest, and freshly ground black pepper.
Serve with toasted bread, pita, crackers, roasted vegetables, or a fresh green salad.