In answer to any questions about whether a Gentile may or should say a prayer of thanks or a blessing to G-d before eating non-kosher food, and/or after eating a non-kosher meal:
Before a Gentile eats or drinks anything that is generally and reasonably accepted and permissible as a normal food, that people would find palatable and not repulsive, it is proper to say words of praise and blessing to G-d, as thanks for that which G-d provides for the person's needs and enjoyment.
An exception would be food that is prohibited to be eaten within the Noahide Code. For example, if a Gentile transgressed by knowingly eating food that had been offered to an idle, or meat that had been severed from a living animal, it would be a further wrongdoing to thank or bless G-d in connection with eating that food. In a similar way, it is forbidden for a Jew to say a blessing for knowingly eating non-kosher food, unless it is an exceptional case when that would be permitted (for example, to save his life).
In the case of halal-certified meat, this has an advantage for Gentiles (as does kosher-certified meat), since there is assurance of not transgressing the prohibition of eating meat that was severed from a living animal. But anyway, regular (non-kosher and non-halel) meat processed from government-certified, large-scale livestock slaughterhouses in the U.S. is usually all OK for Gentiles (Noahides). See
https://asknoah.org/animal-welfare-our-c...-t-grandin