Combine the mayo and coconut milk, whisk together until smooth and there are no lumps. Add apple cider vinegar and whisk to combine.
Crush the garlic clove with a little bit of salt to form a paste. Add to the mayo mixture with some pepper and whisk to combine. Add in the dill and stir to combine.
Refrigerate for at least an hour before using to let thicken up and allow flavors to meld.