I think I would make a poached whole salmon ( you will have leftovers, but it makes a wonderful presentation!) with a dill caper sauce.
Serve a salad of mixed greens with pear or apple slices, a light vinaigrette dressing and topped with blue cheese crumbles and sides of boiled parsleyed new potatoes and a steamed green vegetable...perhaps something seasonal like asparagus.
How about a fruity wine like a reisling or a Rhine wine. You could even make a white sangria using white wine, slices of lemon and apples with some triple sec and either champagne of club soda for a little sparkle.

Dessert ice cream with fresh strawberries...and without an oven you will have to buy your dinner rolls.
Linda C

How about an assortment of kabobs on the grill? You could do some with lamb or beef and some with shrimp and or scallops. Do some vegie kabobs and serve with rice. A nice salad would round out the meal and you can buy whatever you like for desert.

It sounds like you already have some ideas. I think there are so many different things you can make with just the veggie and sea food ingredients that both you and your guest enjoy.

I think a Thai style menu would work well
I also think an Indian style menu would work

If you don't consider it too exotic for your palate give it a try. You don't need oven or microwave to make either of these cuisines and a rice can be cooked in your rice cooker in no time.

Thai Menu:

Some type of soup or your salad would be fine but dress it with a soy peanut and lime dressing. Use lettuce, bean sprouts, scallions and grated carrots to give it an asian feel. Instead of croutons sprinkle some toasted peanuts to finish it off.

For the main course make a thai style shrimp curry. You can make your own curry or buy a store bought (Any Asian market will sell it). Mix the curry with couple of cans of coconut milk. Let it simmer until it's thick, add the shrimps to it, squeeze of lime and garnish with cilantro. Serve it with rice.

You can also make a vegetarian pad thai as yet another dish if you'd like to go elaborate. All you need are some rice noodles that you soak in hot water and then stir fry them with veggies of your choice (even frozen oriental mix will work). Ensure you use garlic and ginger as you stir fry it and add some soy, sugar, lime juice and scramble eggs. Finally add the noodles. Garnish with lime quarters and cilantro

Dessert - Mango Icecream or Sorbet. Hagan Daz makes many exotic versions of this. It's a fitting end to a Thai meal.

Indian Menu

Salad - You can use whatever salad you planned to. Try to find some pappadums that you can fry up (available at Indian stores). Also buy a few dipping sauces (green and red also available at Indian store, known as chutneys). Pappadums can be served with a salad and some dipping sauces as a starter

Main - Make a shrimp curry. Again coconut milk cans and perhaps Patak or any other ready to make curry mix. It's easy and results are very good. Add shrimps, garnish with cilantro

Spicy Potatoes and cautliflower - Make this Indian style. Chop an onion and fry it in oil. Add curry powder to it along with some freshly grated ginger and garlic. Add the potatoes and cauliflower. Cover and cook it until tender. Garnish with cilantro.

Dessert - Mango Icecream will work well with this too.

Everything sounds delicious! Let us know what you decide!

I would NOT serve fish, many people do not like it. Lobster and shrimp, yes, but fish no. Many good suggestions above.
If it is to be casual, how about a large platter with Spinach salad, feta cheese, walnuts or not, and shrimp.( grape tomatoes, onion, etc) Nice crusty loaf of bread. You said she likes low fat, wife eats shrimp, and he eats small portions. That would satisfy all demands. It makes a lovely presentation, and it is filling. Then add your hors d' and desserts.

How about smoked salmon fettucini with a salad and bread. The fettucini can be done on top of the stove and the bread should heat in your oven pretty well. I have a recipe for smoked salmon fettucini if you want it.
Teri