I have some canned oysters, red potatoes and frozen green beans. What should I make? I was thinking of some kind of warm mustard-based salad. Or perhaps a veggie broth-based soup. Any other ideas?
Batter and fry the ingredients. Serve with your favorite sauces.
Soup would be good. A nice cream soup with oysters, potatoes and green beans would be very nice with some good crusty bread and a bottle of unoaked Sauvignon Blanc, or Pino Grigio.
Throw out the oysters and make something with potatoes and green beans? 
The green beans are throwing me, but a baked potato stuffed with oysters, some ham or bacon, garlic, black and/or red pepper, and some parmesan on top would be good. I guess you can throw the beans in too.
Maybe make a gratain.
You could make a chowder.
Great suggestion (minus the ham/bacon.) 
Yeah, I’d have the beans lightly steamed on the side but with a light creamy sauce (they’re frozen, after all), or just lots of butter and seasoning. Baked potato stuffed with oysters has the starring role.
Worst episode of *Chopped *ever.