How to Make It
Preheat the oven to 425°. Cut 1 inch off the top of the garlic. Drizzle with 1 teaspoon of the olive oil and wrap in foil. Roast for 45 minutes, until tender. Let cool. Squeeze out the cloves and mash until smooth.
Peel the cucumber and grate it on the smallest holes of a box grater. Squeeze out all of the liquid. In a small bowl, mix the cucumber with 1 teaspoon of salt and let stand for 10 minutes. Squeeze out all of the liquid again. Combine the garlic and cucumber in a bowl. Add the remaining olive oil as well as all of the remaining ingredients, season with salt and mix well. Refrigerate the tzatziki for at least 1 hour before serving.