Preheat the oven to 400°F.

Cut the top off the head of garlic, leaving the skin on the cloves with only the top part exposed. Drizzle with 1 teaspoon of the olive oil. Wrap in foil and place on a baking sheet.

Peel the onion and cut off the ends. Place on a square of foil, drizzle with the remaining teaspoon of olive oil and wrap in foil. Place on the baking sheet with the head of garlic.

Bake for 40-45 minutes or until the garlic and the onion are tender and lightly browned. Set aside to cool.

In a medium-sized bowl, whisk together the yogurt, mayonnaise, lemon juice, and white wine vinegar until smooth.

Chop the onion and add it to the mayonnaise mixture. Squeeze the roasted garlic into the mixture and stir to combine.

Measure in the Parmesan cheese and black pepper and mix. Taste and add salt to taste.