@MargaretD Your best bet is to ask your Mum how she prefers them. There are dozens of ways to serve oysters. The big divide is whether to serve them raw or cooked. If you are going to serve them raw, be very, very sure they are super fresh - partly so that you don't get food poisoning, but also because if they are not fresh they don't taste as nice.

Personally I like Kilpatrick, which is oysters grilled in open shells with a little Worcestershire sauce, finely chopped bacon and parmesan cheese (very little of each).

Just grilled with a squeeze of lemon is very nice, too.

Can't abide them au naturel myself :-)