Board and skim a cooker hood

First have a look to see if it was made up of hardboard or plaster board, if made of wood see if there room to put plaster boards over the top of the wood, making sure that it still fits in with units round it and because you fitted plasterboard over top of the wood and artex it may look to big for the area round it, if this is the case remove all the wood and see if you can just use plasterboard or you may need to add some more wood to hold the plaster board in place. If it is made up using plaster boards remove plaster boards and start again and plaster. You do not need to use fire plaster boards. It may be best to use as they are a much stronger plaster board hopefully this helps full

Yes I've done a few of them use fire line plaster board and skim