Preheat the oven to 400 degrees F. Slice off the top of the garlic head so that a small amount of each clove shows through. Place the garlic in a small ramekin and drizzle 1 tablespoon of olive oil on top. Sprinkle with a bit of salt. Cover the ramekin with foil and roast the garlic for 30 minutes. Set aside to cool. Once the head is cool enough to handle, squeeze the roasted garlic cloves into a small bowl and smash with a spoon to make a paste.
In a food processor, puree the beans, tahini, olive oil, lemon and water. Season with salt and pepper to taste. Add 1 tablespoon or more of the garlic puree and process until smooth.
You can use as much or as little of the garlic as you prefer. Roasted garlic is much milder than regular garlic but can still pack a punch! I recommend adding 1 tablespoon at a time until the desired flavor is reached.