Ingredients:

• 16 ounces of sour cream (or substitute plain Greek yogurt)
• 3 or 4 cloves of minced or grated garlic (the more garlic – the hotter the tzatziki sauce)
• 1/2 cucumber grated and thinned (drain and discard the juice from the cucumber)
• 2 to 3 tablespoons of red wine vinegar
• 1/4 to 1/2 teaspoon of finely ground white pepper
• 1/2 teaspoon of salt (or more to your taste)

Instructions:

Combine ingredients and stir to blend.
Keep refrigerated. 
Use to top gyros, or to top pork or chicken souvlaki.