All perfect praise is for Allah, the Lord of the worlds. I bear witness that there is no one worthy of worship except Allah, and that Muhammad, peace be upon him, is His slave and Messenger.

The basic rule is that it is permissible to eat in these restaurants as long as you eat halal food. This principle cannot be changed to haraam just because they doubt that they can use the same utensils for cutting and cooking halal meat as they do for cutting and cooking unclean meat without washing the utensils.
However, although this suspicion may not need to be denied, abstinence from food in such restaurants is recommended.

The Prophet (peace and blessings of Allah be upon him) said: There is the best piety in your religion. [Reliable ruler]

Also, there is another narration with weak narrators, but some scholars have classified it as Hasan, in which it is written:

A person will not attain the status of being one of the pious unless he refrains from doing anything that is not sinful, because he is afraid of falling into what is sinful. From.” [Tirmidhi and Ibn Majah]

However, if one basically thinks – just no doubt – that these restaurants use the same utensils for cutting and cooking halal meat as they do for cutting and cooking unclean meat without washing the utensils, then eat in them. Avoiding becomes a responsibility. Because impurity has been transferred to halal meat, and as a result this meat becomes impure. It is not permissible to eat unclean meat without washing it.

Since you sometimes write to us in Arabic, then we refer you to Fatwa 127595 on our Arabic website.

Source: Halal Restaurants Promotional Items