Stir 5 finely grated garlic cloves, 1 tablespoon of the lemon juice, and ½ teaspoon Dijon mustard together in a small bowl until combined. Let sit for 15 minutes for the flavors to meld.
Whisk in ¾ cup mayonnaise until smooth. Taste and season with kosher salt or up to 1 tablespoon more lemon juice as needed.
