Add cilantro, sour cream, lime juice, jalapeño, garlic, and cumin to a blender. If you’re feeling dramatic, pretend you’re on a cooking show—eye contact with the camera optional.
Pulse a few times, then stream in olive oil while blending until smooth and vibrant. Stop when it looks like green sunshine.
Taste and tweak with salt, pepper, or a whisper of sugar. Remember, you want brightness, not a sour punch in the face.
If the mixture is too thick, thin with a teaspoon of water or a splash more lime juice. You’re aiming for a pourable, scoop-friendly consistency.
Transfer to a jar or bowl. Chill for at least 15 minutes if you can wait—the flavors will mingle like old friends.