I remember the first time I cooked dinner for a boyfriend and spent hours on a meatless pasta sauce which he refused to eat simply because there was no meat in it. Fortunately, these days, I don't know anyone who is that determined a carnivore, but I do often cook vegetarian for people who love meat. Even when I cook for mixed groups, I often find that the meat-eaters end up taking some of the food meant for the vegetarians, and a lot of the "vegetarians" choose to eat meat dishes, since I rarely serve just a slab of meat (and some people will say they are vegetarian in case you were planning to serve something weird like brains or sweetbreads!). Pastas, pizzas, Mexican food and curries work wonderfully, in most cases, as do grain-based things like elaborate rice dishes and couscous. I avoid anything which would sound too "health-foody" or "veggie" to someone not used to eating that way - no soy loaves, tempeh, tofu, or steamed vegetable plates. I like using eggplant as a base for sauces as I might use a chicken breast, and I will also do things in crepes, as I find that many people are more comfortable eating things like veggies and grains when they are hidden than they would be if they were just put out on the plate as is.