Fish and chips can be kosher if it`s made with kosher fish in a kosher kitchen. In fact, it was Portuguese Jews who introduced fried fish to England.
Fish and chips can be kosher so long as the fish used is a kosher species and the food is prepared in a kosher kitchen with all kosher ingredients.
The problem with the word "cod" is that it refers to more than one kind of fish, some of which are kosher types and some that aren't. Those "cods" that have fins and scales (when alive) are the kosher kinds. Those kinds that didn't have fins or scales aren't kosher kinds (Deuteronomy ch.14). To be kosher, the fish would have to be a kosher type of fish; and the ingredients (fish, chips, peas) would have to be cooked in kosher pots and pans.
Kosher chips aren't different from other chips other than they've been certified kosher. Most major brands of potato chips are kosher although some flavours might not be kosher.
Kosher fish have fins and scales. I've attached a related link that provides a comprehensive list of kosher fish.
yes
The signs of a kosher fish are scales and fins. If the fish does not have either of these, then it is not a kosher fish. If it does, it is a kosher fish and one may eat it provided, of course, that it was prepared with kosher ingredients. According to "kashrut.com" (see link in related link section), the Grouper is indeed a kosher fish.
Yes, if they were cooked in a vessel that was not used for non-kosher foods. Commercially produced chips require a valid kashrut certification on the packaging.
Yes opa is a kosher fish. Any fish that is born with scales and a dorsal fin is kosher. As long as it hasn't been touched by a non kosher knife
Basa fish, just like all other forms of catfish, is not kosher.
Sawfish, also know as Carpenter Shark, are a family of rays. These fish are not kosher as they do not meet the two requirements of kosher fish: movable fins and easily removed scales.
Rascasse fish is also known as Scorpionfish which is a kosher species. Please see the related link for a comprehensive list of kosher and non-kosher fish.
If it comes from kosher fish such as whitefish, yes. If it comes from non-kosher species such as sturgeon, then no.