Preheat the oven to 170–180°C. Take the 3 heads of garlic and slice crossways a quarter of the way down from the top. Place on a large piece of foil with a drizzle of olive oil, season with salt and pepper, then close the foil. Roast for 20 minutes, until very soft, then squeeze out all the cloves.
Put the roasted garlic into a food processor with the raw garlic clove and blend. Add the egg and yolks one by one, then the olive oil and lemon juice. Season with salt and pepper.