If an order that is unfit for consumption (stale) is brought to you at a restaurant, you have the right not to pay for this dish and to demand that it be replaced with another free of charge.
If the administration of the establishment refuses to replace the dish free of charge, I recommend paying for the dish and documenting the evidence of the violation of your rights: take a photo of the dish, the image on the menu, save the receipt. After that, file a statement about the violation of your rights to the territorial bodies of the State Production and Consumer Service of Ukraine or to the court at your place of residence.