I never make my salad dressing the same twice. But here goes....
In a blender add...
1 "heaping" tablespoon of sour cream, 1 equal amount of (heaping tablespoon) of mayo, 1 garlic clove (a big one if you like lots of garlic), 1/2 teaspoon of salt (I use sea salt), 1/2 teaspoon of fresh pepper (I use a grinder), Add a just a bit more than a quarter cup of lime juice. You can use fresh limes or buy the bottled juice, Depending on how sweet you like your dressing, add enough "real" maple syrup to at least equal or offset the lime juice. I like my dressing sweet., Add a generous handful of fresh cilantro. It has to be fresh. The dried stuff just doesn't cut it.
Blend until garlic and cilantro are pureed. The cilantro should give you a nice green colour. Stick your thumb in to test for sweetness. If too sour add more maple syrup. If too sweet add more lime juice. Dead simple.
I don't use a blender. Instead, I use a hand blender. I put all my ingredients into a 4cup measuring cup and then stick in my "boat motor" and blend away. :-)))
You can use this dressing on almost any mixed green salad. I prefer to use it on "baby spinach". It's healthier. :-)) I add fresh crisp bacon bits that have cooled to the spinach as well as 2 hardboiled eggs that I slice. The eggs & bacon bits give me my protein. :-)))