Begin by collecting all your ingredients on a clean countertop. This will ensure you have everything ready to go.
In a medium mixing bowl, combine the mayonnaise and whole milk Greek yogurt. This combination will create a creamy base for your tartar sauce.
Add the lemon juice, minced capers, diced dill pickles, Dijon mustard, grated garlic, and onion powder to the bowl. Using a whisk or a spoon, mix everything together until well combined.
Sprinkle in some sea salt and freshly ground black pepper to enhance the flavors. Taste the mixture and adjust the seasoning as needed.
Cover the mixing bowl with plastic wrap or transfer the sauce to an airtight container. Place it in the refrigerator for at least 30 minutes. Chilling allows the flavors to meld beautifully.
When you’re ready to serve, give the tartar sauce a good stir. Transfer it to a serving bowl and garnish with freshly chopped chives for a pop of color and flavor.