In a bowl, jar, or small food processor, combine the kefir, Greek yogurt, miso paste, garlic, lemon juice, Dijon, and Worcestershire. Whisk or blend until smooth.
If using a food processor, add the Parmesan and pepper directly. If mixing by hand, stir them in after blending.
Add the olive oil and whisk or pulse again until fully incorporated.
Chill the dressing for 20–30 minutes to help it thicken and allow the flavors to develop.
Taste and adjust consistency or seasoning as needed before serving.