Is it permissible to eat food offered by Muslims in Europe if it was bought from general stores and its ingredients are unknown, for fear of it containing alcohol or unlawful fats?

If the packaging of food products does not state that they contain haram (forbidden) or najis (impure) ingredients, then it is permissible to consume them, as doubt does not render food forbidden. Exaggerating in searching for food ingredients leads to hardship and obsessive thoughts, and Allah Almighty says: "And He has not placed upon you in religion any difficulty," and the Prophet, peace be upon him, said: "Perished are those who meticulously delve into matters." However, if it is known with certainty, or strongly presumed, that they contain haram or najis substances, or if they were purchased with ill-gotten money, then one must avoid them.