This has been an issue for us for some time now. We are (mostly) vegans in a non-vegan world. Most of the people we know and love eat animal products, and we don't love them any less for it; however, we're not going to prepare meat in our home.
(We did serve fish off and on for 6 years. Let's just say that most people, especially children, aren't terribly fond of fish.)
Over the years we've transitioned to more whole foods, to organics, and to eating simple foods. This can make it even harder to feed omnivores, as we no longer use a lot of dairy to help disguise the fact that we aren't eating meat. We no longer take the time to prepare the kind of gourmet vegetarian meals that you might find at Greens in San Francisco or Cafe Flora in Seattle. Brown rice, quinoa, and beans take getting used to.
Tonight we're having last-minute guests; my MIL and her boyfriend. My first thought was, "We can't serve them a vegan vegetable and tofu curry served over quinoa", which was the meal planned for this evening. In general I don't serve such obvious tofu to my guests, and I don't serve quinoa unless I know they are adventurous and interested in healthy eating. Quinoa isn't even my first choice when serving curry, but right now I have a picky eater who won't eat brown rice, so we are eating quinoa with a lot of meals that might go better with rice.
I asked Papa what he wanted to serve. He suggested serving what we would have had Sunday, but this week that's tostadas and we had those last time Abuela came to visit. They are a special meal to us (because of the fried tortillas), but nothing special to her, and anyway, I didn't have leftover beans sitting in the fridge.
Sometimes Sunday supper is a bit fancier; last week we had baked potatoes, roasted mushrooms, steamed broccoli, and for the fish eaters we had halibut. It was definitely decadent. We could have tried to replicate that meal, but were uncertain as to whether either of our guests like fish or mushrooms. We know they like beef, pork, and chicken.
I suggested to Papa that we just go simple: split pea soup, a big green salad, and fresh homemade whole wheat bread. He liked the idea, as did the boys, so that's what I am making. Papa did ask me to splurge on a bottle of white wine, but that meant spending $7 instead of $2 (Papa is pretty fond of the Two Buck Chuck at Trader Joes).
I feel like we are making progress; we at least now can serve simple foods to family. The next hurdle is getting over the idea that we have to serve something complicated to non-family guests. I had a friend once who really had mastered serving simple, inexpensive food to a crowd, and no one ever complained or thought it wasn't fancy enough. It makes me wonder why we seem to think that we need to serve a meal comparable to what one would get at a nice restaurant? I know we aren't the only ones with this mindset; ours is just more complicated because of food choices and food allergies.