Drain and weigh the tofu, pat dry and break it into small pieces.
Place tofu, oil, vinegar, 2 tablespoons water, salt and pepper in a food processor. Blend, stopping to scrape the sides, until as smooth as your machine allows.
If the mixture remains dry or crumbly, add water one teaspoon at a time, up to 2 extra tablespoons. Stop when it is creamy and scoopable; you may not need the full extra amount.
Add chives and parsley and pulse briefly to distribute them. Taste with a vegetable and adjust the seasoning if needed.
Transfer to a covered container and refrigerate until serving. Stir and check the texture again before putting it on the tray.