Peanuts/peanut butter:
Many people are allergic. If you are serving something including peanut butter, make it clear to guests that there are peanuts in it.
Tree nuts:
Same as peanuts, make sure guests are aware of the dish containing nuts.
Meat:
It’s perfectly fine and encouraged to have meat in your dishes, but never serve someone meat if they don’t want it and respect people who may be vegetarian. This is also true for people who follow religions that prohibit pork. Always make sure to have vegetarian options!
Overall, it helps to let guests know what is in the food they are eating. Think about creating cards listing the ingredients of every dish that can be left on the table when you’re serving food, especially if your dish includes eggs, dairy, and/or nut products.