Combine Ingredients: Place the quartered Castelvetrano olives, olive brine, gin, dry vermouth, and lemon peel strips in a small jar or airtight container. Seal it tightly and give it a good shake. Let this flavorful mixture marinate in the refrigerator for at least 30 minutes or up to 1 day for the best taste.

Strain Olives: Carefully strain the olives, making sure to keep both the olives and brine mixture separate. This step is key for achieving that perfect dip consistency!

Blend Cheese Mixture: In a medium bowl, use an electric hand mixer to beat together the cream cheese, blue cheese, kosher salt, black pepper, and 5 tablespoons of the reserved brine mixture. Mix on medium speed until everything is well blended, about 1 minute.

Assemble and Garnish: Transfer the creamy cheese mixture into a small serving bowl. Pour 2 tablespoons of the extra-virgin olive oil into the center, then spoon the reserved marinated olives over the top. Drizzle with the remaining 1 tablespoon of olive oil, and finish with a sprinkle of flaky sea salt and pepper. Serve with crostini for a delightful appetizer!