First, roast the 2 heads of garlic. Heat the oven to 180C/360F. Slice the top off each head of garlic (just a little, so that each clove is exposed) and brush the exposed cloves with olive oil. Wrap in foil and place in the oven for 45 minutes. Remove, unpeel the foil, and leave to cool down for about 15 minutes. Once they are cooled, squeeze out all of the garlic cloves into a small glass or bowl- they will now be soft and creamy and will ooze out of their skins very easily. Mash them with a fork, and then mix in a few tablespoons of extra virgin olive oil. Whisk until emulsified. Mince the additional 1-2 cloves. Heat 1-2 Tblsps of olive oil in a saucepan and lightly saute the garlic until fragrant and soft, but stop before they become brown and toasted. Now add the white beans and the roasted garlic/olive oil mix to the same pan. Mash the beans into the garlic with a wooden spoon and/or a potato masher. Once they are mostly broken up, add the spoonful of yogurt. Use a hand mixer to whip them into a creamy mash, adding additional olive oil or yogurt if the mixture is too thick. Finally, over a medium heat, add the cheese and stir until melted in. Garnish with some chives and serve!