Some ideas....
Cioppino
Bouillabaise
Seafood or fish baked in parchment (I posted some in the archives)
Lobster, Crab, Prawns
Souffle
Frittata
Tofu
Risotto
Stuffed mushrooms (portobellos too),
Big platter of grilled vegetables (zucchini, mushrooms/portobellos, eggplant, onion, asparagus, colorful bell peppers, anaheim chilis, yam or sweet potato slices, other grillable veggies -- just olive oil and season them with pepper since you can't do salt and then drizzle the grilled veggies with balsamic vinegar)
A salad party? with an array of salads, or a make your own salad bar (don't know how many guests you are talking about).
Or a soup and salad party? (Something I've long wanted to do. Soooo many options.)
still thinking.....