Cut the avocados in half, remove the pits, and scoop the flesh into a blender or food processor. Trim away any dark or stringy spots so the crema stays bright green.
2 ripe avocados
Add the sour cream and Greek yogurt to the blender with the avocado. You can use all sour cream or all Greek yogurt if preferred.
1/2 cup sour cream, 1/4 cup plain Greek yogurt
Add the lime juice, cilantro, garlic, olive oil, salt, cumin, and, if using, jalapeño and/or hot sauce.
1/4 cup fresh lime juice, 1/3 cup fresh cilantro leaves, 1 small garlic clove, 1-2 tablespoons olive oil, 1/4-1/2 teaspoon kosher salt, 1/4 teaspoon ground cumin, 1-2 teaspoons finely minced jalapeño, hot sauce
Blend on medium-high until the mixture is completely smooth and silky, scraping down the sides as needed. The texture should be thicker than a dressing but smoother than guacamole.
Add water or milk 1 tablespoon at a time, blending after each addition, until it reaches your desired consistency. Make it slightly thicker for using inside tacos and burritos, or thinner for drizzling.
1-3 tablespoons water or milk
Taste the crema and adjust with more salt, lime juice, or hot sauce as needed. The flavor should be bright, creamy, and lightly tangy.
1/4 cup fresh lime juice, 1/4-1/2 teaspoon kosher salt, hot sauce
Serve immediately, or chill for 20–30 minutes to let the flavors meld and the texture set slightly before serving.