Crab cakes make for a delightful fancy luncheon entree. The crab is luxurious yet delicate of flavor, and the presentation is elegant. You want crab cakes to be the star of the show. Choose side dishes that complement discreetly rather than compete for attention on the plate. Sauces, too, should be subtle and not overwhelm the flavors of the crab.
A lightly dressed green salad rounds out a plate of crab cakes nicely. Keep it simple -- just greens and perhaps a bit of grated carrot or cucumber. Dress with a simple vinaigrette to keep this dish on the light side. For a spring lunch, consider garnishing with fresh edible flowers.
Coleslaw is a classic accompaniment to crab cakes. You can make the traditional mayonnaise-dressed version if you like, although for a fancy luncheon you may wish to opt for a lighter slaw dressed in oil and vinegar instead. Feel free to add or substitute other finely shredded or julienned vegetables to the slaw, such as fennel, red bell pepper, daikon or carrot.
The flavors of corn and crab are famously complementary. Cut corn off the cob and saute with butter; finish with some coarse salt and serve alongside the crab cakes for a simple but rewarding side dish. You could also add scallions to the saute, or opt for a black bean and corn salad for a heartier side.
Potatoes have a mild enough flavor not to compete with crab cakes. Their attraction is in their texture and the way they fill the belly. Silky mashed potatoes, with or without garlic, are a lovely accompaniment to crab cakes for a ladies' luncheon. You could also serve simple roasted potatoes or even oven fries.
Crab cakes do not necessarily need a sauce at all; you can get away with serving each plate with a wedge or two of lemon to squeeze and nothing more. If you desire a side of sauce anyway, you have several to choose from. Simple melted butter will do, as will a mayonnaise and any of its variations, from aioli to roulade to tartar sauce.