Combine the grapes, scallions, cucumber, garlic, parsley and avocado in a food processor and pulse to combine. Add the olive oil and white wine vinegar and pulse again until blended. Add the ice water and pulse again. Add more water if it is not at your desired consistency.
Season with salt and pepper. Serve chilled, topped with toasted almonds and toasted bread on the side, if desired. Can be made 24 hours in advance and stored covered in the refrigerator.