Hosting vegan and vegetarian guests doesn't mean you can't serve meat to your meat-eating visitors. You can make spaghetti and serve it with meatballs and parmesan cheese to your meat-eating guests and serve it without meat or cheese to your vegetarian and vegan guests. This will save you time and the hassle of having to make two completely different meals. Foods like lentils, beans, and tofu make great substitutes for meat because they're hearty and filling. Add them to the vegetarian or vegan dish you're preparing to enhance the flavor and make it more satisfying. Make sure to check if your guests like an ingredient before you include it. If some of your guests are meat eaters and you're cooking dinner, make sure you keep the meat separate from the other ingredients. Some vegetarians and vegans won't eat food that has been contaminated by meat. That includes food that has touched meat or been cooked in the same pan that was used to cook meat.

Summary:
Cook meat for your meat-eating guests. Use popular meat substitutes in your vegetarian and vegan guests' food. Use caution when preparing vegetarian or vegan food around meat.