In a large bowl, combine the sour cream, mayonnaise (or olive oil), lime zest, lime juice, and salt. Stir until smooth.

Toss in the finely shredded cabbage, diagonal slices of green onion, and fresh cilantro leaves.

Gently toss everything together until all the vegetables are thoroughly coated in the dressing.

Set the slaw aside for at least 1 hour to allow the flavors to meld.

Just before serving, give the slaw another light toss and serve.