I ate kosher for a year and a half and here are some ideas >>>
as mentioned above, avoid pork (that includes bacon) and shell fish.
You cannot go wrong with lamb, chicken or fish.
BUT, there is a but:
If you serve meat, you cannot mix dairy with it, and that includes the entire meal, from appetizer to dessert.
It's not as hard as it sounds.
I hardly ever serve three course meals anymore. I start with an appetizer and drink when people arrive.
When we sit down at the table, we go straight to the main course and then, dessert!
Well, that's me.
For starter you could serve a green salad with a vinagrette.
Main course could be chicken, turkey or lamb with vegetables, potatoes and a gravy sauce, and chocolate mousse for dessert (I'm only making suggestions here).
I have always found it easy to fix starters and dinners, but desserts without dairy is a hassle.
You can always serve fish. If so, you can mix fish and dairy, but make sure there are no shrimps or other shellfish around (shrimps have a way of sneaking into so many products. I know because I'm allergic to shrimps).
Your problem hon, is that your plates, casseroles and cutlery is not kosher. So basically, it doesn't really matter.
I think that your in-laws will eat what you serve them but I think it's a good way to show respect for their religion by not serving pork or shell fish.
I have to admit that I once served bread at a kosher dinner where we ate meat - and later realized it contained milk!
Accidents are know to happen but I strongly belive that neither them nor I will go to hell for 1/2 cup of milk! smileys/smile.gif
Good luck on your dinner.