Separate the stems from the cilantro leaves, give the garlic a rough chop, and zest and juice the lime. You should get roughly 2 tablespoon of lime juice.
Add the sour cream, cilantro leaves, garlic, lime zest, lime juice, and salt to a food processor or small blender.
Blend until smooth and all of the ingredients are well combined. I love the consistency of this recipe, but if you want a thinner sauce add a little more lime juice or a splash of water and continue to blend to reach your desired consistency.